Prealgebra 2e — Original English

Divide Whole Numbers

Use Division Notation

So far we have explored addition, subtraction, and multiplication. Now let’s consider division. Suppose you have the 12 cookies in Figure 1 and want to package them in bags with 4 cookies in each bag. How many bags would we need?

An image of three rows of four cookies to show twelve cookies.

You might put 4 cookies in first bag, 4 in the second bag, and so on until you run out of cookies. Doing it this way, you would fill 3 bags.

An image of 3 bags of cookies, each bag containing 4 cookies.

In other words, starting with the 12 cookies, you would take away, or subtract, 4 cookies at a time. Division is a way to represent repeated subtraction just as multiplication represents repeated addition.

Instead of subtracting 4 repeatedly, we can write

12÷4

We read this as twelve divided by four and the result is the quotient of 12 and 4. The quotient is 3 because we can subtract 4 from 12 exactly 3 times. We call the number being divided the dividend and the number dividing it the divisor. In this case, the dividend is 12 and the divisor is 4.

In the past you may have used the notation 412, but this division also can be written as 12÷4,12/4,124. In each case the 12 is the dividend and the 4 is the divisor.

Translate from math notation to words.

64÷8 427 428

Solution

Solution

  • We read this as sixty-four divided by eight and the result is the quotient of sixty-four and eight.
  • We read this as forty-two divided by seven and the result is the quotient of forty-two and seven.
  • We read this as twenty-eight divided by four and the result is the quotient of twenty-eight and four.

Model Division of Whole Numbers

As we did with multiplication, we will model division using counters. The operation of division helps us organize items into equal groups as we start with the number of items in the dividend and subtract the number in the divisor repeatedly.

Model the division: 24÷8.

Solution

Solution

To find the quotient 24÷8, we want to know how many groups of 8 are in 24.

Model the dividend. Start with 24 counters.
An image of 24 counters placed randomly.

The divisor tell us the number of counters we want in each group. Form groups of 8 counters.
An image of 24 counters, all contained in 3 bubbles, each bubble containing 8 counters.

Count the number of groups. There are 3 groups.

24÷8=3

Divide Whole Numbers

We said that addition and subtraction are inverse operations because one undoes the other. Similarly, division is the inverse operation of multiplication. We know 12÷4=3 because 3·4=12. Knowing all the multiplication number facts is very important when doing division.

We check our answer to division by multiplying the quotient by the divisor to determine if it equals the dividend. In Example 2, we know 24÷8=3 is correct because 3·8=24.

Divide. Then check by multiplying. 42÷6 729 763

Solution

Solution

  • Illustrates division of 42 by 6, with calculation and verification steps.
    42÷6
    Divide 42 by 6. 7
    Check by multiplying.
    7·6
    42
  • Demonstration of dividing 72 by 9, including the calculation and verification steps.
    729
    Divide 72 by 9. 8
    Check by multiplying.
    8·9
    72
  • Step-by-step demonstration of dividing 63 by 7 using long division, including a multiplication check.
    763
    Divide 63 by 7. 9
    Check by multiplying.
    9·7
    63

What is the quotient when you divide a number by itself?

1515=1because1·15=15

Dividing any number (except 0) by itself produces a quotient of 1. Also, any number divided by 1 produces a quotient of the number. These two ideas are stated in the Division Properties of One.

Divide. Then check by multiplying:

  1. 11÷11
  2. 191
  3. 17
Solution

Solution

  • 11÷11
    A number divided by itself is 1. 1
    Check by multiplying.
    1·11
    11
  • 191
    A number divided by 1 equals itself. 19
    Check by multiplying.
    19·1
    19
  • 17
    A number divided by 1 equals itself. 7
    Check by multiplying.
    7·1
    7

Suppose we have $0, and want to divide it among 3 people. How much would each person get? Each person would get $0. Zero divided by any number is 0.

Now suppose that we want to divide $10 by 0. That means we would want to find a number that we multiply by 0 to get 10. This cannot happen because 0 times any number is 0. Division by zero is said to be undefined.

These two ideas make up the Division Properties of Zero.

Another way to explain why division by zero is undefined is to remember that division is really repeated subtraction. How many times can we take away 0 from 10? Because subtracting 0 will never change the total, we will never get an answer. So we cannot divide a number by 0.

Divide. Check by multiplying: 0÷3 10/0.

Solution

Solution

  • Demonstration and verification of the property that zero divided by any non-zero number equals zero.
    0÷3
    Zero divided by any number is zero. 0
    Check by multiplying.
    0·3
    0
  • Illustration of division by zero being undefined, showing a mathematical expression and its resulting state.
    10/0
    Division by zero is undefined. undefined

When the divisor or the dividend has more than one digit, it is usually easier to use the 412 notation. This process is called long division. Let’s work through the process by dividing 78 by 3.

Divide the first digit of the dividend, 7, by the divisor, 3.
The divisor 3 can go into 7 two times since 2×3=6. Write the 2 above the 7 in the quotient. A long division problem showing 78 divided by 3. The initial step highlights dividing the 7 by 3, resulting in 2 as the first digit of the quotient.
Multiply the 2 in the quotient by 3 and write the product, 6, under the 7. A long division problem showing the first step of dividing 78 by 3. The digit 7 is divided by 3, resulting in a quotient of 2 and a remainder of 1 after subtracting 6.
Subtract that product from the first digit in the dividend. Subtract 76. Write the difference, 1, under the first digit in the dividend. A long division problem showing the first step of dividing 78 by 3. The digit 7 is divided by 3, resulting in a quotient of 2 and a remainder of 1 after subtracting 6.
Bring down the next digit of the dividend. Bring down the 8. A long division problem showing the next step of dividing 78 by 3. The digit 6 is subtracted from 7 resulting in 1. The digit 8 is brought down for a resulting number of 18.
Divide 18 by the divisor, 3. The divisor 3 goes into 18 six times. A long division problem showing the next step of dividing 78 by 3. In this step, the number 18 is divided by 3. The resulting number 6 is placed above the long division problem, revealing the overall answer to be 26.
Write 6 in the quotient above the 8.
Multiply the 6 in the quotient by the divisor and write the product, 18, under the dividend. Subtract 18 from 18. A long division problem showing the final step of dividing 78 by 3. The number 18 can be fully divisible by 3, leaving zero remainders and and overall answer of 26.

We would repeat the process until there are no more digits in the dividend to bring down. In this problem, there are no more digits to bring down, so the division is finished.

So78÷3=26.

Check by multiplying the quotient times the divisor to get the dividend. Multiply 26×3 to make sure that product equals the dividend, 78.

216×3___78

It does, so our answer is correct.

Divide 2,596÷4. Check by multiplying:

Solution

Solution

Let's rewrite the problem to set it up for long division. A long division problem set up to divide 2596 by 4.
Divide the first digit of the dividend, 2, by the divisor, 4. A long division problem set up to divide 2596 by 4. The first digit, 2, is colored red.
Since 4 does not go into 2, we use the first two digits of the dividend and divide 25 by 4. The divisor 4 goes into 25 six times.
We write the 6 in the quotient above the 5. A long division problem showing 2596 being divided by 4. The first digit of the quotient, 6, is shown above the 5, indicating that 25 divided by 4 is 6.
Multiply the 6 in the quotient by the divisor 4 and write the product, 24, under the first two digits in the dividend. A long division problem showing 2596 divided by 4. The first step of the division shows that 4 goes into 25 six times, with 24 (in red) written below 25, indicating the product of 4 and 6.
Subtract that product from the first two digits in the dividend. Subtract 2524. Write the difference, 1, under the second digit in the dividend. A long division problem showing 2596 divided by 4. The first step of the division shows that 4 goes into 25 six times, with 24 (in red) written below 25, indicating the product of 4 and 6. After subtracting 24 from 25, the resulting remainder is 1.
Now bring down the 9 and repeat these steps. There are 4 fours in 19. Write the 4 over the 9. Multiply the 4 by 4 and subtract this product from 19. A long division problem showing 2596 divided by 4. The next step of the division brings down the third digit in the quotient, 9, resulting in 19, the next number to be divided by 4. 4 can go into 19 four times (16, written below 19). The number four is written above 2596. Finally 19 minus 16 equals a remainder of 3.
Bring down the 6 and repeat these steps. There are 9 fours in 36. Write the 9 over the 6. Multiply the 9 by 4 and subtract this product from 36. Long division of 2596 by 4, yielding a result of 649 with no remainder, demonstrating the step-by-step process of division.
So 2,596÷4=649.
Check by multiplying.
A multiplication problem in which 649 is multiplied by 4, resulting in 2596.

It equals the dividend, so our answer is correct.

Divide 4,506÷6. Check by multiplying:

Solution

Solution

Let's rewrite the problem to set it up for long division. A long division problem showing 4506 divided by 6.
First we try to divide 6 into 4. A long division problem showing 4506 divided by 6. The first digit, 4, is in red.
Since that won't work, we try 6 into 45.
There are 7 sixes in 45. We write the 7 over the 5.
A long division problem with 4506 being divided by 6. The number 7 is shown as the first digit of the quotient above the 5, indicating that 45 divided by 6 is 7 with a remainder.
Multiply the 7 by 6 and subtract this product from 45. An illustration of long division, specifically the initial step where 45 is divided by 6, yielding 7, and 42 is subtracted to find the remainder of 3.
Now bring down the 0 and repeat these steps. There are 5 sixes in 30.
Write the 5 over the 0. Multiply the 5 by 6 and subtract this product from 30.
An illustration of long division, specifically the step in which the digit 0 is brought down with the remainder 3 resulting in 30 which can then be further divided by 6. 30 can be fully divided by 6 five times. Thus, the number 5 is written above the division problem, resulting in a remainder of 0.
Now bring down the 6 and repeat these steps. There is 1 six in 6.
Write the 1 over the 6. Multiply 1 by 6 and subtract this product from 6.
An illustration of long division, showing the final step in which the digit 6 is brought down with the remainder 0 resulting in 6 which can then be divided by 6 one time. Thus, the number 1 is written above the division problem, resulting in a final remainder of 0 and a final answer of 751.
Check by multiplying.
A vertical multiplication problem showing 751 multiplied by 6, with the correct result of 4,506 marked by a checkmark.

It equals the dividend, so our answer is correct.

Divide 7,263÷9. Check by multiplying.

Solution

Solution

Let's rewrite the problem to set it up for long division. A long division problem showing 7263 divided by 9.
First we try to divide 9 into 7. A long division problem showing 7263 divided by 9. THe first digit, 7, is in red.
Since that won't work, we try 9 into 72. There are 8 nines in 72.
We write the 8 over the 2.
A long division problem showing 7263 divided by 9. The image shows the first step, dividing the first two digits, 72, by 9, resulting in 8 which is written above the division line.
Multiply the 8 by 9 and subtract this product from 72. A long division problem showing 7263 divided by 9. The image shows the next step, in which 9 is multiplied by 8, resulting in 72, which is then written below the intitial 72, creating a remainder of 0.
Now bring down the 6 and repeat these steps. There are 0 nines in 6.
Write the 0 over the 6. Multiply the 0 by 9 and subtract this product from 6.
A long division problem showing 7263 divided by 9. The image shows the next step in which the digit 6 is brought down. Six is not divisible by 9, so 0 is written above the division problem. Nine multiplied by 0 equals 0, which is written below, creating a remainder of 6.
Now bring down the 3 and repeat these steps. There are 7 nines in 63. Write the 7 over the 3.
Multiply the 7 by 9 and subtract this product from 63.
A long division problem showing 7263 divided by 9. The image shows the next step in which the final digit 3 is brought down next to the number 6, resulting in 63. 63 is divisible by 9 7 times. Thus, 7 is written above the division line, leaving zero remainder and a final answer of 807.
Check by multiplying.
A multiplication problem in which 807 is multipled by 9 to equal 7,263 with a checkmark next to the answer.

It equals the dividend, so our answer is correct.

So far all the division problems have worked out evenly. For example, if we had 24 cookies and wanted to make bags of 8 cookies, we would have 3 bags. But what if there were 28 cookies and we wanted to make bags of 8? Start with the 28 cookies as shown in Figure 2.

An image of 28 cookies placed at random.

Try to put the cookies in groups of eight as in Figure 3.

An image of 28 cookies. There are 3 circles, each containing 8 cookies, leaving 3 cookies outside the circles.

There are 3 groups of eight cookies, and 4 cookies left over. We call the 4 cookies that are left over the remainder and show it by writing R4 next to the 3. (The R stands for remainder.)

To check this division we multiply 3 times 8 to get 24, and then add the remainder of 4.

3×8___24+4___28

Divide 1,439÷4. Check by multiplying.

Solution

Solution

Let's rewrite the problem to set it up for long division. A mathematical expression showing the long division of 1439 by 4.
First we try to divide 4 into 1. Since that won't work, we try 4 into 14.
There are 3 fours in 14. We write the 3 over the 4.
A long division problem is shown, indicating the calculation of 1439 divided by 4, with the first digit of the quotient, 3, placed above the '14' of 1439.
Multiply the 3 by 4 and subtract this product from 14. A long division problem is shown where 1439 is divided by 4. In this step, multiplying 4 and 3 equals 12, which is written below the first two digits, 14. 14 minus 12 equals a remainder of 2.
Now bring down the 3 and repeat these steps. There are 5 fours in 23.
Write the 5 over the 3. Multiply the 5 by 4 and subtract this product from 23.
A long division problem is shown where 1439 is divided by 4. In this step, the digit 3 is brought down next to the remainder 2, resulting in the number 23. 23 is divisible by 4 5 times. 5 is written above and the number 20 is written below 23, resulting in a remainder of 3.
Now bring down the 9 and repeat these steps. There are 9 fours in 39.
Write the 9 over the 9. Multiply the 9 by 4 and subtract this product from 39.
There are no more numbers to bring down, so we are done.
The remainder is 3.
A long division problem is shown where 1439 is divided by 4. In this step, the final digit 9 is brought down next to the previous remainder of 3, creating the number 39. The number 4 can only go into 39 nine times, resulting in the number 36, creating a final remainder of 3. The answer written above is then 359R3.
Check by multiplying.
A multiplication problem showing 359 times 4, resulting in 1,436. This number is then added to 3, resulting in a final answer of 1,439.

So 1,439÷4 is 359 with a remainder of 3. Our answer is correct.

Divide and then check by multiplying: 1,461÷13.

Solution

Solution

Let's rewrite the problem to set it up for long division. 131,461
First we try to divide 13 into 1. Since that won't work, we try 13 into 14.
There is 1 thirteen in 14. We write the 1 over the 4.
A long division problem showing 1461 divided by 13 with the number 1 written above the long division line.
Multiply the 1 by 13 and subtract this product from 14. A long division problem is shown, with 1461 being divided by 13. The first step of the division is completed, showing 13 subtracted from 14, resulting in a remainder of 1. The quotient above is 1.
Now bring down the 6 and repeat these steps. There is 1 thirteen in 16.
Write the 1 over the 6. Multiply the 1 by 13 and subtract this product from 16.
A long division problem in progress, showing 1461 divided by 13. The current steps result in a partial quotient of 11 with a remainder of 3, indicating the full calculation is incomplete.
Now bring down the 1 and repeat these steps. There are 2 thirteens in 31.
Write the 2 over the 1. Multiply the 2 by 13 and subtract this product from 31. There are no more numbers to bring down, so we are done.
The remainder is 5. 1,462÷13 is 112 with a remainder of 5.
A long division problem in progress, showing 1461 divided by 13. This final step shows the answer is 112 with a remainder of 5.
Check by multiplying.
A handwritten arithmetic problem demonstrating the check for a division, where the quotient (112) is multiplied by the divisor (13), and the remainder (5) is added to reach the original number (1461).

Our answer is correct.

Divide and check by multiplying: 74,521÷241.

Solution

Solution

Let's rewrite the problem to set it up for long division. 24174,521
First we try to divide 241 into 7. Since that won’t work, we try 241 into 74. That still won’t work, so we try 241 into 745. Since 2 divides into 7 three times, we try 3.
Since 3×241=723, we write the 3 over the 5 in 745.
Note that 4 would be too large because 4×241=964, which is greater than 745.
Multiply the 3 by 241 and subtract this product from 745. A long division problem showing 74521 divided by 241. In this step, the first three digits 745 are divided by 241, which allows the student to write 4 above the division line, and subtract 723 from 745, creating a remainder of 22.
Now bring down the 2 and repeat these steps. 241 does not divide into 222.
We write a 0 over the 2 as a placeholder and then continue.
A long division problem showing 74521 divided by 241. In this step, the fourth digit, 2, is written next to the previous remainder of 22, creating the number 222, which is not divisible by 241. Thus, the number zero is written above the division line.
Now bring down the 1 and repeat these steps. Try 9. Since 9×241=2,169,
we write the 9 over the 1. Multiply the 9 by 241 and subtract this product from 2,221.
A handwritten long division problem showing 74521 divided by 241, resulting in a quotient of 309 with a remainder of 52.
There are no more numbers to bring down, so we are finished. The remainder is 52. So 74,521÷241
is 309 with a remainder of 52.
Check by multiplying.
A multiplication problem in which 309 is multiplied by 241. With the added remainder of 52, the final answer is 74,521.

Sometimes it might not be obvious how many times the divisor goes into digits of the dividend. We will have to guess and check numbers to find the greatest number that goes into the digits without exceeding them.

Translate Word Phrases to Math Notation

Earlier in this section, we translated math notation for division into words. Now we’ll translate word phrases into math notation. Some of the words that indicate division are given in Table 19.

Operation Word Phrase Example Expression
Division divided by
quotient of
divided into
12 divided by 4
the quotient of 12 and 4
4 divided into 12
12÷4
124
12/4
412

Translate and simplify: the quotient of 51 and 17.

Solution

Solution

The word quotient tells us to divide.

the quotient of 51 and 17Translate.51÷17Divide.3

We could just as correctly have translated the quotient of 51 and 17 using the notation

1751or5117.

Divide Whole Numbers in Applications

We will use the same strategy we used in previous sections to solve applications. First, we determine what we are looking for. Then we write a phrase that gives the information to find it. We then translate the phrase into math notation and simplify it to get the answer. Finally, we write a sentence to answer the question.

Cecelia bought a 160-ounce box of oatmeal at the big box store. She wants to divide the 160 ounces of oatmeal into 8-ounce servings. She will put each serving into a plastic bag so she can take one bag to work each day. How many servings will she get from the big box?

Solution

Solution

We are asked to find the how many servings she will get from the big box.

Demonstrates the process of solving a division word problem: phrasing, math notation, simplification, and final answer.
Write a phrase. 160 ounces divided by 8 ounces
Translate to math notation. 160÷8
Simplify by dividing. 20
Write a sentence to answer the question. Cecelia will get 20 servings from the big box.

Key Concepts

Operation Notation Expression Read as Result
Division ÷
ab
ba
a/b
12÷4
124
412
12/4
Twelve divided by four the quotient of 12 and 4
  • Division Properties of One
    • Any number (except 0) divided by itself is one. a÷a=1
    • Any number divided by one is the same number. a÷1=a
  • Division Properties of Zero
    • Zero divided by any number is 0. 0÷a=0
    • Dividing a number by zero is undefined. a÷0 undefined
  • Divide whole numbers.
    1. Divide the first digit of the dividend by the divisor.
      If the divisor is larger than the first digit of the dividend, divide the first two digits of the dividend by the divisor, and so on.
    2. Write the quotient above the dividend.
    3. Multiply the quotient by the divisor and write the product under the dividend.
    4. Subtract that product from the dividend.
    5. Bring down the next digit of the dividend.
    6. Repeat from Step 1 until there are no more digits in the dividend to bring down.
    7. Check by multiplying the quotient times the divisor.

Section Exercises

Practice Makes Perfect

Use Division Notation

In the following exercises, translate from math notation to words.

54÷9

Solution

fifty-four divided by nine; the quotient of fifty-four and nine

567

328

Solution

thirty-two divided by eight; the quotient of thirty-two and eight

642

48÷6

Solution

forty-eight divided by six; the quotient of forty-eight and six

639

763

Solution

sixty-three divided by seven; the quotient of sixty-three and seven

72÷8

Model Division of Whole Numbers

In the following exercises, model the division.

15÷5

Solution


Three distinct clusters of grey circles, each enclosed by a blob-like outline, illustrating concepts of grouping or classification.

10÷5

147

Solution


Two irregular shapes enclose groups of grey circles, depicting distinct clusters or collections of items. This image could represent separated data points or cellular groupings.

186

420

Solution


An illustration showing multiple clusters of gray circles, with each group enclosed by an irregular outline, representing data grouping or segmentation.

315

24÷6

Solution


An illustration showing clusters of gray circles, with each group enclosed by an irregular outline, representing data grouping or segmentation.

16÷4

Divide Whole Numbers

In the following exercises, divide. Then check by multiplying.

18÷2

Solution

9

14÷2

273

Solution

9

303

428

Solution

7

436

455

Solution

9

355

72/8

Solution

9

864

357

Solution

5

42÷7

1515

Solution

1

1212

43÷43

Solution

1

37÷37

231

Solution

23

291

19÷1

Solution

19

17÷1

0÷4

Solution

0

0÷8

50

Solution

undefined

90

260

Solution

undefined

320

120

Solution

0

160

72÷3

Solution

24

57÷3

968

Solution

12

786

5465

Solution

93

4528

924÷7

Solution

132

861÷7

5,2266

Solution

871

3,7768

431,324

Solution

7,831

546,855

7,209÷3

Solution

2,403

4,806÷3

5,406÷6

Solution

901

3,208÷4

42,816

Solution

704

63,624

91,8819

Solution

10,209

83,2568

2,470÷7

Solution

352 R6

3,741÷7

855,305

Solution

6,913 R1

951,492

431,1745


Solution

86,234 R4

297,2774

130,016÷3

Solution

43,338 R2

105,609÷2

155,735

Solution

382 R5

4,93321

56,883÷67

Solution

849

43,725/75

30,144314

Solution

96

26,145÷415

273542,195

Solution

1,986 R17

816,243÷462

Mixed Practice

In the following exercises, simplify.

15(204)

Solution

3,060

74·391

256184

Solution

72

305262

719+341

Solution

1,060

647+528

25875

Solution

35

1104÷23

Translate Word Phrases to Algebraic Expressions

In the following exercises, translate and simplify.

the quotient of 45 and 15

Solution

45 ÷ 15; 3

the quotient of 64 and 16

the quotient of 288 and 24

Solution

288 ÷ 24; 12

the quotient of 256 and 32

Divide Whole Numbers in Applications

In the following exercises, solve.

Trail mix Ric bought 64 ounces of trail mix. He wants to divide it into small bags, with 2 ounces of trail mix in each bag. How many bags can Ric fill?

Solution

Ric can fill 32 bags.

Crackers Evie bought a 42 ounce box of crackers. She wants to divide it into bags with 3 ounces of crackers in each bag. How many bags can Evie fill?

Astronomy class There are 125 students in an astronomy class. The professor assigns them into groups of 5. How many groups of students are there?

Solution

There are 25 groups.

Flower shop Melissa’s flower shop got a shipment of 152 roses. She wants to make bouquets of 8 roses each. How many bouquets can Melissa make?

Baking One roll of plastic wrap is 48 feet long. Marta uses 3 feet of plastic wrap to wrap each cake she bakes. How many cakes can she wrap from one roll?

Solution

Marta can wrap 16 cakes from 1 roll.

Dental floss One package of dental floss is 54 feet long. Brian uses 2 feet of dental floss every day. How many days will one package of dental floss last Brian?

Mixed Practice

In the following exercises, solve.

Miles per gallon Susana’s hybrid car gets 45 miles per gallon. Her son’s truck gets 17 miles per gallon. What is the difference in miles per gallon between Susana’s car and her son’s truck?

Solution

The difference is 28 miles per gallon.

Distance Mayra lives 53 miles from her mother’s house and 71 miles from her mother-in-law’s house. How much farther is Mayra from her mother-in-law’s house than from her mother’s house?

Field trip The 45 students in a Geology class will go on a field trip, using the college’s vans. Each van can hold 9 students. How many vans will they need for the field trip?

Solution

They will need 5 vans for the field trip

Potting soil Aki bought a 128 ounce bag of potting soil. How many 4 ounce pots can he fill from the bag?

Hiking Bill hiked 8 miles on the first day of his backpacking trip, 14 miles the second day, 11 miles the third day, and 17 miles the fourth day. What is the total number of miles Bill hiked?

Solution

Bill hiked 50 miles

Reading Last night Emily read 6 pages in her Business textbook, 26 pages in her History text, 15 pages in her Psychology text, and 9 pages in her math text. What is the total number of pages Emily read?

Patients LaVonne treats 12 patients each day in her dental office. Last week she worked 4 days. How many patients did she treat last week?

Solution

LaVonne treated 48 patients last week.

Scouts There are 14 boys in Dave’s scout troop. At summer camp, each boy earned 5 merit badges. What was the total number of merit badges earned by Dave’s scout troop at summer camp?

Writing Exercises

Contact lenses Jenna puts in a new pair of contact lenses every 14 days. How many pairs of contact lenses does she need for 365 days?

Solution

Jenna uses 26 pairs of contact lenses, but there is 1 day left over, so she needs 27 pairs for 365 days.

Cat food One bag of cat food feeds Lara’s cat for 25 days. How many bags of cat food does Lara need for 365 days?

Everyday Math

Explain how you use the multiplication facts to help with division.

Solution

Answers may vary. Using multiplication facts can help you check your answers once you’ve finished division.

Oswaldo divided 300 by 8 and said his answer was 37 with a remainder of 4. How can you check to make sure he is correct?

Self Check

After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

A self-assessment checklist for division and algebraic expressions, allowing students to rate their understanding as confident, needing some help, or not understanding.

Overall, after looking at the checklist, do you think you are well-prepared for the next Chapter? Why or why not?

Chapter Review Exercises

Introduction to Whole Numbers

Identify Counting Numbers and Whole Numbers

In the following exercises, determine which of the following are (a) counting numbers (b) whole numbers.

0,2,99

Solution
  1. 2, 99
  2. 0, 2, 99

0,3,25

0,4,90

Solution
  1. 4, 90
  2. 0, 4, 90

0,1,75

Model Whole Numbers

In the following exercises, model each number using base-10 blocks and then show its value using place value notation.

258

Solution


The image shows sets of hundred blocks, sets of blocks of 10, and single blocks. Below, the types of blocks and their total values are organized in a table with a total block values.

104

Identify the Place Value of a Digit

In the following exercises, find the place value of the given digits.

472,981

  1. 8
  2. 4
  3. 1
  4. 7
  5. 2
Solution
  1. tens
  2. hundred thousands
  3. ones
  4. ten thousands
  5. thousands

12,403,295

  1. 4
  2. 0
  3. 1
  4. 9
  5. 3

Use Place Value to Name Whole Numbers

In the following exercises, name each number in words.

5,280

Solution

Five thousand, two hundred eighty

204,614

5,012,582

Solution

Five million, twelve thousand, five hundred eighty-two

31,640,976

Use Place Value to Write Whole Numbers

In the following exercises, write as a whole number using digits.

six hundred two

fifteen thousand, two hundred fifty-three

Solution

15,253

three hundred forty million, nine hundred twelve thousand, sixty-one

Solution

340,912,061

two billion, four hundred ninety-two million, seven hundred eleven thousand, two

Round Whole Numbers

In the following exercises, round to the nearest ten.

412

Solution

410

648

3,556

Solution

3,560

2,734

In the following exercises, round to the nearest hundred.

38,975

Solution

39,000

26,849

81,486

Solution

81,500

75,992

Add Whole Numbers

Use Addition Notation

In the following exercises, translate the following from math notation to words.

4+3

Solution

four plus three; the sum of four and three

25+18

571+629

Solution

five hundred seventy-one plus six hundred twenty-nine; the sum of five hundred seventy-one and six hundred twenty-nine

10,085+3,492

Model Addition of Whole Numbers

In the following exercises, model the addition.

6+7

Solution


A row of light gray vertical panels with subtle patterns, reflecting on a darker surface below, creating an abstract and minimalist composition.

38+14

Add Whole Numbers

In the following exercises, fill in the missing values in each chart.

A table with 11 rows down and 11 rows across. The first row and first column are headers and include the numbers 0 through 9 both across and down, with a plus sign in the first cell. The numbers across in the second row down appear as follows: 0,0,  1, null, 3, 4, null, 6, 7, null, 9. The numbers across in the third row down appear as follows: 1, 1, 2, 3, 4, null, null, 7, 8, 9, null. The numbers in the fourth row down appear across as follows: 2, null, 3,4,5,6,7,8, null, 10, 11. The numbers across in the fifth row down appear as follows: 3, 3, null, 5, null, 7, 8, null, 10, null 12. The numbers across in the sixth row down appear as follows: 4, 4, 5, null, null, 8, 9,null, null, 12, null. The numbers across in the seventh row down appear as follows: 5, 5, null, 7, 8, null null, 11, null, 13, null. The numbers across in the eighth row down appear as follows:6, 6, 7, 8, null, 10, null, null, 13, null, 15. The numbers across in the ninth row down appear as follows: null, null, 9, null, null, 12, 13, null, 15, 16. The numbers across in the tenth row down appear as follows: 8,8,9,null, 11, null, null, 14, null, eleventh row down appear as follows: 9, 9, 10, 11, null, 13, 14, null, null, 17, null.
Solution


A clear and simple addition table showing the sums of numbers from 0 to 9. It's a fundamental tool for understanding basic arithmetic and number relationships in a grid format.

This table is 5 rows and 8 columns. The top row is a header row and includes the numbers 3 through 9, one number to each cell. The rows down include 6, 7, 8, and 9. There is a plus sign in the first cell. All cells are null.

In the following exercises, add.

0+19 19+0

Solution
  1. 19
  2. 19

0+480 480+0

7+6 6+7

Solution
  1. 13
  2. 13

23+18 18+23

44+35

Solution

79

63+29

96+58

Solution

154

375+591

7,281+12,546

Solution

19,827

5,280+16,324+9,731

Translate Word Phrases to Math Notation

In the following exercises, translate each phrase into math notation and then simplify.

the sum of 30 and 12

Solution

30 + 12; 42

11 increased by 8

25 more than 39

Solution

39 + 25; 64

total of 15 and 50

Add Whole Numbers in Applications

In the following exercises, solve.

Shopping for an interview Nathan bought a new shirt, tie, and slacks to wear to a job interview. The shirt cost $24, the tie cost $14, and the slacks cost $38. What was Nathan’s total cost?

Solution

$76

Running Jackson ran 4 miles on Monday, 12 miles on Tuesday, 1 mile on Wednesday, 8 miles on Thursday, and 5 miles on Friday. What was the total number of miles Jackson ran?

In the following exercises, find the perimeter of each figure.

An image of a rectangle that is 8 feet tall and 15 feet wide.
Solution

46 feet

An image of a right triangle that has a base of 12 centimeters, height of 5 centimeters, and diagonal hypotenuse of 13 centimeters.

Subtract Whole Numbers

Use Subtraction Notation

In the following exercises, translate the following from math notation to words.

145

Solution

fourteen minus five; the difference of fourteen and five

4015

351249

Solution

three hundred fifty-one minus two hundred forty-nine; the difference between three hundred fifty-one and two hundred forty-nine

5,7242,918

Model Subtraction of Whole Numbers

In the following exercises, model the subtraction.

184

Solution


The image uses blocks to demonstrate the subtraction problem 18 – 4.

4129

Subtract Whole Numbers

In the following exercises, subtract and then check by adding.

85

Solution

3

127

239

Solution

14

4621

8259

Solution

23

11087

539217

Solution

322

415296

1,020640

Solution

380

8,3553,947

10,00015

Solution

9,985

54,92535,647

Translate Word Phrases to Math Notation

In the following exercises, translate and simplify.

the difference of nineteen and thirteen

Solution

19 − 13; 6

subtract sixty-five from one hundred

seventy-four decreased by eight

Solution

74 − 8; 66

twenty-three less than forty-one

Subtract Whole Numbers in Applications

In the following exercises, solve.

Temperature The high temperature in Peoria one day was 86 degrees Fahrenheit and the low temperature was 28 degrees Fahrenheit. What was the difference between the high and low temperatures?

Solution

58 degrees Fahrenheit

Savings Lynn wants to go on a cruise that costs $2,485. She has $948 in her vacation savings account. How much more does she need to save in order to pay for the cruise?

Multiply Whole Numbers

Use Multiplication Notation

In the following exercises, translate from math notation to words.

8×5

Solution

eight times five; the product of eight and five

6·14

(10)(95)

Solution

ten times ninety-five; the product of ten and ninety-five

54(72)

Model Multiplication of Whole Numbers

In the following exercises, model the multiplication.

2×4

Solution


The image uses circles to demonstrate the multiplication problem of 2 × 4.

3×8

Multiply Whole Numbers

In the following exercises, fill in the missing values in each chart.

A table with 10 rows down and 10 rows across. The first row and first column are headers and include the numbers 0 through 9 both across and down, with a plus sign in the first cell. The numbers across in the second row down appear as follows: 0, 0, 0, 0, 0, 0, null, 0, null, 0,0. The numbers across in the third row down appear as follows: 1, 0, 1, 2, null, 4, 5, 6, 7, null, 9.  The numbers across in the fourth row down appear as follows: 2, 0, null, 4, null, 8, 10, null, 14, 16, null. The numbers across in the fifth row down appear as follows: 3, null, 3, null, 9, null, null, 18, null, 24, null. The numbers across in the sixth row down appear as follows: 4, 0, 4, 0, 12, null, null, 24, null, null, 36.  The numbers across in the seventh row down appear as follows:5, 0, 5, 10, null, 20, null, 30, 35, 40, 45. The numbers across in the eighth row down appear as follows: 6, null, null, 12, 18, null, null, 36, 42, null, 54.  The numbers across in the ninth row down appear as follows: 7, 0, 7, null, 21, null, 35, null, null, 56, 63. The numbers in the tenth row down appear as follows: 8, 0, 8, 16, null, 32, null, 48, null, 64, null. The numbers in the eleventh row down appear across as follows: 9, null, null, 18, 27, 36, null, null, 63, 72, null.
Solution


A multiplication table from 0x0 to 9x9, displaying the product of each row and column intersection. The table is shaded with alternating light and dark grey rows for readability. Perfect for learning basic math.

An image of a table with 8 columns and 5 rows. The cells in the first row and first column are shaded darker than the other cells. The first row has the values “x; 3; 4; 5; 6; 7; 8; 9”. The first column has the values “x;  6; 7; 8; 9”. All other cells are null.

In the following exercises, multiply.

0·14

Solution

0

(256)0

1·99

Solution

99

(4,789)1

7·4 4·7

Solution
  1. 28
  2. 28

(25)(6)

9,261×3

Solution

27,783

48·76

64·10

Solution

640

1,000(22)

162×493

Solution

79,866

(601)(943)

3,624×517

Solution

1,873,608

10,538·22

Translate Word Phrases to Math Notation

In the following exercises, translate and simplify.

the product of 15 and 28

Solution

15(28); 420

ninety-four times thirty-three

twice 575

Solution

2(575); 1,150

ten times two hundred sixty-four

Multiply Whole Numbers in Applications

In the following exercises, solve.

Gardening Geniece bought 8 packs of marigolds to plant in her yard. Each pack has 6 flowers. How many marigolds did Geniece buy?

Solution

48 marigolds

Cooking Ratika is making rice for a dinner party. The number of cups of water is twice the number of cups of rice. If Ratika plans to use 4 cups of rice, how many cups of water does she need?

Multiplex There are twelve theaters at the multiplex and each theater has 150 seats. What is the total number of seats at the multiplex?

Solution

1,800 seats

Roofing Lewis needs to put new shingles on his roof. The roof is a rectangle, 30 feet by 24 feet. What is the area of the roof?

Divide Whole Numbers

Use Division Notation

Translate from math notation to words.

54÷9

Solution

fifty-four divided by nine; the quotient of fifty-four and nine

42/7

728

Solution

seventy-two divided by eight; the quotient of seventy-two and eight

648

Model Division of Whole Numbers

In the following exercises, model.

8÷2

Solution


The image shows clusters of grey circles to demonstrate 8 divided by 2.

312

Divide Whole Numbers

In the following exercises, divide. Then check by multiplying.

14÷2

Solution

7

328

52÷4

Solution

13

2626

971

Solution

97

0÷52

100÷0

Solution

undefined

3555

3828÷6

Solution

638

311,519

750525

Solution

300 R5

5,166÷42

Translate Word Phrases to Math Notation

In the following exercises, translate and simplify.

the quotient of 64 and 16

Solution

64 ÷ 16; 4

the quotient of 572 and 52

Divide Whole Numbers in Applications

In the following exercises, solve.

Ribbon One spool of ribbon is 27 feet. Lizbeth uses 3 feet of ribbon for each gift basket that she wraps. How many gift baskets can Lizbeth wrap from one spool of ribbon?

Solution

9 baskets

Juice One carton of fruit juice is 128 ounces. How many 4 ounce cups can Shayla fill from one carton of juice?

Chapter Practice Test

Determine which of the following numbers are

  1. counting numbers
  2. whole numbers.

0,4,87

Solution
  1. 4, 87
  2. 0, 4, 87

Find the place value of the given digits in the number 549,362.

  1. 9
  2. 6
  3. 2
  4. 5

Write each number as a whole number using digits.

  1. six hundred thirteen
  2. fifty-five thousand two hundred eight
Solution
  1. 613
  2. 55,208

Round 25,849 to the nearest hundred.

Simplify.

45+23

Solution

68

6542

85÷5

Solution

17

1,000×8

9058

Solution

32

73+89

(0)(12,675)

Solution

0

634+255

09

Solution

0

8128

14579

Solution

66

299+836

7·475

Solution

3,325

8,528+704

35(14)

Solution

490

260

733291

Solution

442

4,9161,538

495÷45

Solution

11

52×983

Translate each phrase to math notation and then simplify.

The sum of 16 and 58

Solution

16 + 58; 74

The product of 9 and 15

The difference of 32 and 18

Solution

32 − 18; 14

The quotient of 63 and 21

Twice 524

Solution

2(524); 1,048

29 more than 32

50 less than 300

Solution

300 − 50; 250

In the following exercises, solve.

LaVelle buys a jumbo bag of 84 candies to make favor bags for her son’s party. If she wants to make 12 bags, how many candies should she put in each bag?

Last month, Stan’s take-home pay was $3,816 and his expenses were $3,472. How much of his take-home pay did Stan have left after he paid his expenses?

Solution

Stan had $344 left.

Each class at Greenville School has 22 children enrolled. The school has 24 classes. How many children are enrolled at Greenville School?

Clayton walked 12 blocks to his mother’s house, 6 blocks to the gym, and 9 blocks to the grocery store before walking the last 3 blocks home. What was the total number of blocks that Clayton walked?

Solution

Clayton walked 30 blocks.

dividend
When dividing two numbers, the dividend is the number being divided.
divisor
When dividing two numbers, the divisor is the number dividing the dividend.
quotient
The quotient is the result of dividing two numbers.