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Adding Decimals

The methods of adding decimals is almost the same as addition of integers. The only difference is that decimal addition has a decimal point. After adding the numbers and writing the answer, count the number of digits to the right of the decimal point of the number having the most decimal positions. The decimal point is always positioned this number of digits from the right-most digit of the answer.

23.65

+ 5.43

2908

The most digits to the right of the decimal point for any number is 2. They are 6 and 5 or 4 and 3.

Answer with correct decimal point placement: 29.08

47.39

+ 16.742

64132

Digits to the right of the decimal point for the numbers added is 3. They are 7, 4 and 2.

Answer with correct decimal point placement: 64.132

12.309

+ 6.742

19051

Digits to the right of the decimal point for the numbers added is 3. They are 3, 0, and 9 or 7, 4 and 2.

Answer with correct decimal point placement: 19.051

13.230

+ 5.74

1897

Decimal positions that are zeros on the far right of added numbers are not counted.

Digits to the right of the decimal point for any number is 2. They are 2 and 3 or 7 and 4.

Answer with correct decimal point placement: 18.97

The reason far right-most zeros are not counted for decimal point positioning is that zeros have no value for the number and could be removed:

13.23 is the same value as 13.230 or 13.2300.

If the zero isn’t a far right-most zero it has place value and is counted:

13.023 is not equal to 13.203 is not equal to 13.230.

.023 = 23/1,000

.203 = 203/1,000

.230 = 23/100

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