Prealgebra 2e — Original English

Subtract Whole Numbers

Use Subtraction Notation

Suppose there are seven bananas in a bowl. Elana uses three of them to make a smoothie. How many bananas are left in the bowl? To answer the question, we subtract three from seven. When we subtract, we take one number away from another to find the difference. The notation we use to subtract 3 from 7 is

73

We read 73 as seven minus three and the result is the difference of seven and three.

Translate from math notation to words: 81 2614.

Solution

Solution

  • We read this as eight minus one. The result is the difference of eight and one.
  • We read this as twenty-six minus fourteen. The result is the difference of twenty-six and fourteen.

Model Subtraction of Whole Numbers

A model can help us visualize the process of subtraction much as it did with addition. Again, we will use base-10 blocks. Remember a block represents 1 and a rod represents 10. Let’s start by modeling the subtraction expression we just considered, 73.

This table visually demonstrates the subtraction of 3 from 7 using blocks, illustrating each step from initial modeling to the final mathematical result.
We start by modeling the first number, 7. The image shows seven outlined gray boxes with the number 7 written underneath them.
Now take away the second number, 3. We'll circle 3 blocks to show that we are taking them away. The image shows three gray outlined boxes circled in red, a gap, and then four gray outlined boxes not circled.
Count the number of blocks remaining. Four light gray squares with dark outlines and subtle drop shadows are arranged horizontally on a clean white background.
There are 4 ones blocks left. We have shown that 73=4.

Model the subtraction: 82.

Solution

Solution

82 means the difference of 8 and 2.
Model the first, 8. A row of eight light blue squares with dark borders, with the number '8' centered directly below them on a white background.
Take away the second number, 2. A row of eight light blue squares with dark borders. The first two squares are circled in red.
Count the number of blocks remaining. A row of six light blue squares with dark borders.
There are 6 ones blocks left. We have shown that 82=6.

Model the subtraction: 138.

Solution

Solution

Model the first number, 13. We use 1 ten and 3 ones. Ten light blue blocks aligned horizontally, followed by a gap and then three more blocks. This simple graphic might illustrate quantities, data segments, or a step-by-step process.
Take away the second number, 8. However, there are not 8 ones, so we will exchange the 1 ten for 10 ones. Two groups of light blue squares with dark outlines are displayed on a white background, one group has 10 squares and the other has 3 squares, with the numbers 10 and 3 placed below them respectively.
Now we can take away 8 ones. A row of light blue squares. Ten squares are enclosed by a magenta oval, with an arrow pointing left underneath, indicating a loop or repetition. Four additional squares are to the right.
Count the blocks remaining. A row of five light blue squares with dark outlines. There is a small gap between the first two squares and the rest of the three squares.
There are five ones left. We have shown that 138=5.

As we did with addition, we can describe the models as ones blocks and tens rods, or we can simply say ones and tens.

Model the subtraction: 4326.

Solution

Solution

Because 4326 means 43 take away 26, we begin by modeling the 43.
An image containing two items. The first item is 4 horizontal rods containing 10 blocks each. The second item is 3 individual blocks.

Now, we need to take away 26, which is 2 tens and 6 ones. We cannot take away 6 ones from 3 ones. So, we exchange 1 ten for 10 ones.
This figure contains two groups. The first group on the left includes 3 rows of blue base 10 blocks and 1 red row of 10 blocks. This is labeled 4 tens. Alongside the first row of ten blocks are 3 individual blocks. This is labeled 3 ones. An arrow points to the right to the second group in which there are three rows of 10 base blocks labeled 3 tens. Next to this is a row of 3 blue individual blocks and two rows each with five individual blocks in red. This is labeled 13 ones.

Now we can take away 2 tens and 6 ones.
This image includes one row of base ten blocks at the top of the image; Next to it are seven individual blocks. Below this, is a group of two rows of base ten blocks, and two rows of 3 individual blocks with a circle around all. The arrow points to the right and shows one row of ten blocks and seven individual blocks underneath.

Count the number of blocks remaining. There is 1 ten and 7 ones, which is 17.

4326=17

Subtract Whole Numbers

Addition and subtraction are inverse operations. Addition undoes subtraction, and subtraction undoes addition.

We know 73=4 because 4+3=7. Knowing all the addition number facts will help with subtraction. Then we can check subtraction by adding. In the examples above, our subtractions can be checked by addition.

73=4because4+3=7138=5because5+8=134326=17because17+26=43
Subtract and then check by adding:
  1. 97
  2. 83.
Solution

Solution

Illustration of subtracting 7 from 9, with expression, result, and addition-based verification.
97
Subtract 7 from 9. 2
Check with addition.
2+7=9
This table demonstrates the subtraction of 3 from 8, including the problem, its result, and a verification step.
83
Subtract 3 from 8. 5
Check with addition.
5+3=8

To subtract numbers with more than one digit, it is usually easier to write the numbers vertically in columns just as we did for addition. Align the digits by place value, and then subtract each column starting with the ones and then working to the left.

Subtract and then check by adding: 8961.

Solution

Solution

This table illustrates the step-by-step process of subtracting two-digit numbers, including lining up, subtracting by place value, and checking with addition.
Write the numbers so the ones and tens digits line up vertically. 89 61____
Subtract the digits in each place value.

Subtract the ones: 9-1=8
Subtract the tens: 8-6=2
89 61____ 28
Check using addition.
28 +61____ 89

Our answer is correct.

When we modeled subtracting 26 from 43, we exchanged 1 ten for 10 ones. When we do this without the model, we say we borrow 1 from the tens place and add 10 to the ones place.

Subtract: 4326.

Solution

Solution

A step-by-step visual guide demonstrating the process of subtracting numbers with borrowing, including textual instructions and corresponding illustrations.
Write the numbers so each place value lines up vertically. A vertical subtraction problem is displayed, showing 43 minus 26, set up for manual calculation. A horizontal line underneath indicates where the answer would be placed.
Subtract the ones. We cannot subtract 6 from 3, so we borrow 1 ten. This makes 3 tens and 13 ones. We write these numbers above each place and cross out the original digits. A vertical subtraction problem setup, demonstrating the regrouping (borrowing) method for 43 minus 26. The 4 is shown as 3, and the 3 as 13, preparing for the subtraction calculation.
Now we can subtract the ones. 136=7. We write the 7 in the ones place in the difference. A vertical subtraction problem setup, demonstrating the regrouping (borrowing) method for 43 minus 26. The 4 is shown as 3, and the 3 as 13, preparing for the subtraction calculation to result in the answer 7.
Now we subtract the tens. 32=1. We write the 1 in the tens place in the difference. A handwritten example demonstrating subtraction with borrowing, showing 43 minus 26 equals 17.
Check by adding.

A vertical addition problem showing 17 plus 26 equals 43, with a black checkmark verifying the correct answer. The numbers are neatly aligned, demonstrating a basic arithmetic operation.
Our answer is correct.

Subtract and then check by adding: 20764.

Solution

Solution

This table illustrates the step-by-step process of subtracting multi-digit numbers with borrowing, followed by a verification step.
Write the numbers so each place value lines up vertically. A vertical subtraction problem shows 207 minus 64, with a line beneath to indicate the answer should follow.
Subtract the ones. 74=3.
Write the 3 in the ones place in the difference.
A vertical subtraction problem of 207 - 64, demonstrating the initial borrowing from the hundreds to the tens place, and the calculation of the units digit as 3.
Subtract the tens. We cannot subtract 6 from 0 so we borrow 1 hundred and add 10 tens to the 0 tens we had. This makes a total of 10 tens. We write 10 above the tens place and cross out the 0. Then we cross out the 2 in the hundreds place and write 1 above it. A vertical subtraction problem of 207 - 64, demonstrating the initial borrowing from the hundreds to the tens place, and the calculation of the units digit as 3.
Now we subtract the tens. 106=4. We write the 4 in the tens place in the difference. A vertical subtraction problem demonstrating the borrowing method. The calculation shows 107 minus 64, resulting in 43, with regrouping indicated by the crossed-out digits and new values above them.
Finally, subtract the hundreds. There is no digit in the hundreds place in the bottom number so we can imagine a 0 in that place. Since 10=1, we write 1 in the hundreds place in the difference. A vertical subtraction problem showing 207 minus 64, with borrowing steps indicated, resulting in the answer 143.
Check by adding.
A vertical addition problem of 143 + 64, with the placement of 1 over the first digit 1 of 143. This results in the answer 207.
Our answer is correct.

Subtract and then check by adding: 910586.

Solution

Solution

Step-by-step guide demonstrating multi-digit subtraction with borrowing, showing instructional text alongside visual examples and a final check.
Write the numbers so each place value lines up vertically. A vertical subtraction problem is presented, with 910 on top and 586 below it, separated by a horizontal line, and a minus sign to the left of 586, indicating the operation.
Subtract the ones. We cannot subtract 6 from 0, so we borrow 1 ten and add 10 ones to the 0 ones we had. This makes 10 ones. We write a 0 above the tens place and cross out the 1. We write the 10 above the ones place and cross out the 0. Now we can subtract the ones. 106=4. A vertical subtraction problem setup, showing 910 minus 586. The image illustrates the first step of borrowing for the ones column, where the '1' in the tens place becomes '0' and the '0' becomes '10'.
Write the 4 in the ones place of the difference. A vertical subtraction problem setup, showing 910 minus 586. The image illustrates the first step of borrowing for the ones column, where the '1' in the tens place becomes '0' and the '0' becomes '10', resulting in the answer 4.
Subtract the tens. We cannot subtract 8 from 0, so we borrow 1 hundred and add 10 tens to the 0 tens we had, which gives us 10 tens. Write 8 above the hundreds place and cross out the 9. Write 10 above the tens place. A vertical subtraction problem setup, showing 910 minus 586. The image illustrates the first step of borrowing for the ones column, where the '9' in the hundreds place becomes '8', the '1' in the tens place becomes '10' and the '0' becomes '10'. This results in an answer of 4.
Now we can subtract the tens. 108=2. An image illustrating long subtraction with borrowing: 910 minus 586. The borrowing steps for units and tens are shown, yielding 4 and 2 respectively. However, the final result of 24 is incorrect, as it should be 324.
Subtract the hundreds place. 85=3 Write the 3 in the hundreds place in the difference. Vertical subtraction problem 910 - 586 = 324, demonstrating the regrouping technique used to solve it.
Check by adding.

A vertical addition problem showing 324 plus 586 equals 910. The carries are indicated above the numbers, and a checkmark confirms the correctness of the sum.

Our answer is correct.

Subtract and then check by adding: 2,162479.

Solution

Solution

Write the numbers so each place value lines up vertically. A vertical subtraction problem of 2162 minus 479.
Subtract the ones. Since we cannot subtract 9 from 2, borrow 1 ten and add 10 ones to the 2 ones to make 12 ones. Write 5 above the tens place and cross out the 6. Write 12 above the ones place and cross out the 2. A vertical subtraction problem of 2162 minus 479, illustrating the borrowing process. The '2' in the ones place becomes '12' by borrowing from the '6' in the tens place, which then becomes '5'.
Now we can subtract the ones. 129=3
Write 3 in the ones place in the difference. A vertical subtraction problem where 2162 is being subtracted by 479. The image shows the first step of borrowing, where the '2' in the ones place becomes '12' and the '6' in the tens place becomes '5', resulting in '3' for the ones column.
Subtract the tens. Since we cannot subtract 7 from 5, borrow 1 hundred and add 10 tens to the 5 tens to make 15 tens. Write 0 above the hundreds place and cross out the 1. Write 15 above the tens place. A vertical subtraction problem where 2162 is being subtracted by 479. The image shows the steps of borrowing, where the '2' in the ones place becomes '12' and the '6' in the tens place becomes '5' which then is crossed out to become '15', and the '1' in the hundreds place becomes '0'. This results in '3' written in the answer's ones place.
Now we can subtract the tens. 157=8
Write 8 in the tens place in the difference. A vertical subtraction problem where 2162 is being subtracted by 479. The image shows the steps of borrowing, where the '2' in the ones place becomes '12' and the '6' in the tens place becomes '15', and the '1' in the hundreds place becomes '0'. This results in '3' written in the answer's ones place and an '8' written in the tens place.
Now we can subtract the hundreds. A step-by-step vertical subtraction problem demonstrating the borrowing or regrouping method, with 2062 minus 479 resulting in 1583.
Write 6 in the hundreds place in the difference. A long subtraction problem showing 2162 minus 479, with borrowing indicated, resulting in 1683. The final answer, 1683, is partially highlighted in red (the '6').
Subtract the thousands. There is no digit in the thousands place of the bottom number, so we imagine a 0. 10=1. Write 1 in the thousands place of the difference. A long subtraction problem showing 2162 minus 479, with borrowing indicated, resulting in 1683. The final answer, 1683, is partially highlighted in red (the '1').
Check by adding.

11,61813+479______2,162

Our answer is correct.

Translate Word Phrases to Math Notation

As with addition, word phrases can tell us to operate on two numbers using subtraction. To translate from a word phrase to math notation, we look for key words that indicate subtraction. Some of the words that indicate subtraction are listed in Table 12.

Operation Word Phrase Example Expression
Subtraction minus 5 minus 1 51
difference the difference of 9 and 4 94
decreased by 7 decreased by 3 73
less than 5 less than 8 85
subtracted from 1 subtracted from 6 61

Translate and then simplify:

  1. the difference of 13 and 8
  2. subtract 24 from 43
Solution

Solution

  • The word difference tells us to subtract the two numbers. The numbers stay in the same order as in the phrase.

    Steps to translate a verbal mathematical phrase into an expression and simplify it to its numerical value.
    the difference of 13 and 8
    Translate. 138
    Simplify. 5
  • The words subtract from tells us to take the first number away from the second. We must be careful to get the order correct.

    This table illustrates the steps to translate a word problem into a mathematical expression and then simplify it to a numerical result.
    subtract 24 from 43
    Translate. 4324
    Simplify. 19

Subtract Whole Numbers in Applications

To solve applications with subtraction, we will use the same plan that we used with addition. First, we need to determine what we are asked to find. Then we write a phrase that gives the information to find it. We translate the phrase into math notation and then simplify to get the answer. Finally, we write a sentence to answer the question, using the appropriate units.

The temperature in Chicago one morning was 73 degrees Fahrenheit. A cold front arrived and by noon the temperature was 27 degrees Fahrenheit. What was the difference between the temperature in the morning and the temperature at noon?

Solution

Solution

We are asked to find the difference between the morning temperature and the noon temperature.

This table illustrates the step-by-step process of translating a word phrase into a subtraction problem and calculating its numerical difference.
Write a phrase. the difference of 73 and 27
Translate to math notation. Difference tells us to subtract. 7327
Then we do the subtraction. The vertical subtraction of 73 by 27, resulting in 46, with the borrowing process from the tens column (7 to 6, 3 to 13) clearly shown.
Write a sentence to answer the question. The difference in temperatures was 46 degrees Fahrenheit.

A washing machine is on sale for $399. Its regular price is $588. What is the difference between the regular price and the sale price?

Solution

Solution

We are asked to find the difference between the regular price and the sale price.

This table illustrates the step-by-step process of solving a subtraction word problem, from phrasing to the final answer.
Write a phrase. the difference between 588 and 399
Translate to math notation. 588399
Subtract. A three column subtraction problem is set up to show 588 minus 399. With borrowing indicated, the answer is 189.
Write a sentence to answer the question. The difference between the regular price and the sale price is $189.

Key Concepts

Operation Notation Expression Read as Result
Subtraction 73 seven minus three the difference of 7 and 3
  • Subtract whole numbers.
    1. Write the numbers so each place value lines up vertically.
    2. Subtract the digits in each place value. Work from right to left starting with the ones place. If the digit on top is less than the digit below, borrow as needed.
    3. Continue subtracting each place value from right to left, borrowing if needed.
    4. Check by adding.

Practice Makes Perfect

Use Subtraction Notation

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

159

Solution

fifteen minus nine; the difference of fifteen and nine

1816

4235

Solution

forty-two minus thirty-five; the difference of forty-two and thirty-five

8364

675350

Solution

six hundred seventy-five minus three hundred fifty; the difference of six hundred seventy-five and three hundred fifty

790525

Model Subtraction of Whole Numbers

In the following exercises, model the subtraction.

52

Solution


The image uses blocks to demonstrate the subtraction problem 5 - 2.

84

63

Solution


The image uses blocks to demonstrate the subtraction problem 6- 3.

75

185

Solution


The image uses blocks to demonstrate the subtraction problem 18 - 5.

198

178

Solution


The image uses blocks to demonstrate the subtraction problem 17 - 8.

179

3513

Solution


The image uses blocks to demonstrate the subtraction problem 35 - 13.

3211

6147

Solution


The image uses blocks to demonstrate the subtraction problem 61 - 47.

5536

Subtract Whole Numbers

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

94

Solution

5

93

80

Solution

8

20

3816

Solution

22

4521

8552

Solution

33

9947

493370

Solution

123

268106

5,9464,625

Solution

1,321

7,7753,251

7547

Solution

28

6359

461239

Solution

222

486257

525179

Solution

346

542288

6,3182,799

Solution

3,519

8,1533,978

2,150964

Solution

1,186

4,245899

43,6508,982

Solution

34,668

35,1627,885

Translate Word Phrases to Algebraic Expressions

In the following exercises, translate and simplify.

The difference of 10 and 3

Solution

10 − 3; 7

The difference of 12 and 8

The difference of 15 and 4

Solution

15 − 4; 11

The difference of 18 and 7

Subtract 6 from 9

Solution

9 − 6; 3

Subtract 8 from 9

Subtract 28 from 75

Solution

75 − 28; 47

Subtract 59 from 81

45 decreased by 20

Solution

45 − 20; 25

37 decreased by 24

92 decreased by 67

Solution

92 − 67; 25

75 decreased by 49

12 less than 16

Solution

16 − 12; 4

15 less than 19

38 less than 61

Solution

61 − 38; 23

47 less than 62

Mixed Practice

In the following exercises, simplify.

7647

Solution

29

9153

256184

Solution

72

305262

719+341

Solution

1,060

647+528

2,0151,993

Solution

22

2,0201,984

In the following exercises, translate and simplify.

Seventy-five more than thirty-five

Solution

75 + 35; 110

Sixty more than ninety-three

13 less than 41

Solution

41 − 13; 28

28 less than 36

The difference of 100 and 76

Solution

100 − 76; 24

The difference of 1,000 and 945

Subtract Whole Numbers in Applications

In the following exercises, solve.

Temperature The high temperature on June 2 in Las Vegas was 80 degrees and the low temperature was 63 degrees. What was the difference between the high and low temperatures?

Solution

The difference between the high and low temperature was 17 degrees

Temperature The high temperature on June 1 in Phoenix was 97 degrees and the low was 73 degrees. What was the difference between the high and low temperatures?

Class size Olivia’s third grade class has 35 children. Last year, her second grade class had 22 children. What is the difference between the number of children in Olivia’s third grade class and her second grade class?

Solution

The difference between the third grade and second grade was 13 children.

Class size There are 82 students in the school band and 46 in the school orchestra. What is the difference between the number of students in the band and the orchestra?

Shopping A mountain bike is on sale for $399. Its regular price is $650. What is the difference between the regular price and the sale price?

Solution

The difference between the regular price and sale price is $251.

Shopping A mattress set is on sale for $755. Its regular price is $1,600. What is the difference between the regular price and the sale price?

Savings John wants to buy a laptop that costs $840. He has $685 in his savings account. How much more does he need to save in order to buy the laptop?

Solution

John needs to save $155 more.

Banking Mason had $1,125 in his checking account. He spent $892. How much money does he have left?

Everyday Math

Road trip Noah was driving from Philadelphia to Cincinnati, a distance of 502 miles. He drove 115 miles, stopped for gas, and then drove another 230 miles before lunch. How many more miles did he have to travel?

Solution

157 miles

Test Scores Sara needs 350 points to pass her course. She scored 75,50,70,and80 on her first four tests. How many more points does Sara need to pass the course?

Writing Exercises

Explain how subtraction and addition are related.

Solution

Answers may vary.

How does knowing addition facts help you to subtract numbers?

Self Check

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

A self-assessment table for subtraction skills, allowing students to rate their proficiency as 'Confidently', 'With some help', or 'No-I don't get it!' across five different learning objectives.

What does this checklist tell you about your mastery of this section? What steps will you take to improve?

difference
The difference is the result of subtracting two or more numbers.