Adding and Subtracting Decimals

Adding and subtracting involving decimals is best tackled after your child has grasped the concept of tenths and hundredths. Assuming this concept is understood, then the essential step of lining up the decimal points when adding or subtracting should be more easily followed.

Be sure the decimal point is included in the answer

When zero doesn’t mean anything

You can review with your child how, when adding or subtracting whole numbers, zeros can be added to the left of a number without affecting its value.

The same logic can be applied to the tenths, hundredths, and thousandths using the base 10 blocks as a visual reference.

This will help when adding and subtracting numbers with different numbers of digits.

Worksheets

• Adding Decimals e.g. 3.563 + 6.451
• Adding Decimals e.g. 3.754 + 2.1
• Subtracting Decimals e.g. 4.234 - 3.438
• Subtracting Decimals e.g. 6.892 - 3.2