Adding and Subtracting Decimals 3-5 Solve problems involving addition and subtraction of decimals.

To add decimals Line up the decimal points and add the columns from right to left. Annex zeros to make the same number of places behind the decimal points. Place a decimal point in the answer directly below the other decimal points.

Example 1 0.64 + 0.39 Line up the decimal points. Add the columns. + 0.39 __________________________ 1.03

Example 2 5.74 + 3.3 Line up the decimal points. Add the columns. 5.74 + 3.30 Annex a zero in empty spot. _____________________________ 9.04

Example 3 28 + 2.562 Line up the decimal points. Add the columns. 28.000 Annex zeros in empty spots. + 2.562 _____________________________ 30.562

To subtract decimals Line up the decimal points. Annex zeros to make the same number of places behind the decimal points. Subtract the columns from right to left, regrouping if necessary. Place a decimal point in the answer directly below the other decimal points.

Example 1 0.37 0.86 – 0.49 Line up the decimal points Regroup the tenths. Subtract the columns. 0.86 - 0.49 __________________________ 7 16 0.37

Example 2 12.36 – 4.081 Line up the decimal points Regroup the tenths. Subtract the columns. 12.360 Annex zeros in empty spots. - 4.081 __________________________ 8.279 0 12 2 15 10

Example 3 9 – 2.872 Line up the decimal points Regroup the tenths. Subtract the columns. 8 9 9 10 9.000 Annex zeros in empty spots. - 2.872 __________________________ 6.128

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