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Chapter 4—Decimals

4-5 Subtracting Decimals
When you complete the work for this section, you should be able to:
  • Explain how to align decimal points when subtracting decimal numbers.
  • Demonstrate an ability to subtract decimal numbers without making errors.

The procedures for subtracting decimals is nearly the same as for whole numbers and integers. The only difference is that you must align the decimal points in order to make sure you are subtracting like place values—ones from ones, tenths from tenths, hundreds from hundreds, hundredths from hundredths, and so on.

Procedure
Step 1: Write the decimal values in vertical form, aligning the decimal points.

fig040401.gif (1232 bytes)

Note: Aligning the decimal points automatically aligns the place values—ones with ones, tenths with tenths, and hundredths with hundredths.

 Step 2: Perform the subtraction, placing the decimal point directly in line with the other decimal points in the problem.

fig040402.gif (1284 bytes)

Example 1

Problem

8.4 – 4.3 = _____
Procedure
  1. Write the decimal values in vertical form, aligning the decimal points vertically.

     8.4
  – 4.3

  1. Perform the subtraction, placing the decimal point directly in line with the other decimal points in the problem.
      8.4
  – 4.3
     4.1
Solution

8.4 – 4.3 = 4.1

Example 2

Problem

1.68 – 0.24 = _____
Procedure
  1. Write the decimal values in vertical form, aligning the decimal points vertically.

    1.68
  – 0.24

  1. Perform the subtraction, placing the decimal point directly in line with the other decimal points in the problem.
      1.68
  –  0.24
     1.44
Solution

1.68 – 0.24 = 1.44

Example 3

Problem

1 – 0.02 = _____
Procedure
  1. Write the decimal values in vertical form, aligning the decimal points vertically.

     1.00
  – 0.02

  1. Perform the subtraction, placing the decimal point directly in line with the other decimal points in the problem.
    1.00
  – 0.02
     0.98
Solution

1 – 0.02 =  0.98

Examples and Exercises

Subtracting Decimals

Use these interactive examples and exercises to strengthen your understanding and build your skills:

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