Subtraction of Decimals

When we subtract decimals, there are three basic principles that we need to remember:

  1. Write the numbers one below the other making sure that you line up the decimal points.

  2. Add zeroes if necessary to get the same number of decimal places in each number and then subtract as if the numbers were whole numbers.

  3. Place the decimal point in your answer so that it is lined up with the decimal points in the numbers subtracted.


As in addition, you can make sure that your decimal is in the right place if all of your numbers have the same number of decimal places.


The same is true with whole numbers. Make any whole number a decimal by putting a decimal point on the right and then add zeroes so that both numbers have the same number of decimal places.

Examples:

1.

47.3 - 23.7

Explanation:

 

06.1
47.3
-23.7
23.6

 

The decimal places are lined up and each number has the same number of decimal places, so the numbers are ready to be subtracted.

Place the decimal in your answer directly under the decimals in the problem.

2.

147.23 - 86.57

Explanation:

 

146111
147.23
-86.57
60.66

 

Write your numbers, making sure that you line up the decimals.

Subtract the numbers as if they were whole numbers.

Place the decimal in your answer directly under the decimals in the problem.

3.

46.5 - 24.37

Explanation:

 

46.41
46.50
-24.37
22.13

 

Write your numbers, making sure that you line up the decimals.

Add one zero to 46.5 so that both numbers have the same number of decimal places.

Subtract the numbers as if they were whole numbers.

Place the decimal in your answer directly under the decimals in the problem.

4.

546.725 - 376.47

Explanation:

 

4160610
546.725
-376.470
170.255

 

Write your numbers, making sure that you line up the decimals.

Add one zero to 376.47 so that both numbers have the same number of decimal places.

Subtract the numbers as if they were whole numbers.

Place the decimal in your answer directly under the decimals in the problem.

5.

97 - 43.76

Explanation:

 

96091
97.00
-43.76
53.24

 

Make 97 a decimal by placing a decimal point on the right for 97.

Add two zeroes to 97. so that both numbers have two decimal places.

Subtract the numbers as if they were whole numbers.

Place the decimal in your answer directly under the decimals in the problem.

6.

987.65 - 769

Explanation:

 

971.65
987.65
-769.00
218.65

 

Make 769 a decimal by placing a decimal point on the right for 769.

Add two zeroes to 769. so that both numbers have two decimal places.

Subtract the numbers as if they were whole numbers.

Place the decimal in your answer directly under the decimals in the problem.