How to Add and Multiply Decimals

Adding and multiplying decimals is similar to adding and multiplying whole numbers. However, decimals require an additional step of aligning the decimal point before performing the operation. Here's how to add and multiply decimals:

Adding Decimals: 1. Write down the decimals one under the other with the decimal points aligned. 2. Add zeros to the right of the decimal points, so that both numbers have the same number of decimal places. 3. Add the numbers as you would with whole numbers, carrying over as necessary. 4. Place the decimal point in the answer directly below the decimal point in the numbers being added.

Example: 0.45 + 1.23

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1.68

Multiplying Decimals: 1. Multiply the two numbers as you would with whole numbers, ignoring the decimal points. 2. Count the total number of decimal places in both numbers being multiplied. 3. Place the decimal point in the answer so that the total number of decimal places is equal to the number obtained in step 2.

Example: 2.5 x 1.2

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30 (ignore decimal points)

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3.0 (place decimal point as 2 decimal places were present in the original numbers)

Remember to practice, and double-check your answers by using a calculator or rechecking your work manually.