Operations on Decimal Fractions 1

Addition & Subtraction

Decimal fractions are just an extension of the place value system which is used to represent whole numbers. Decimal fractions can be added and subtracted like whole numbers and the result interpreted similarly. Like in the case of whole numbers, the numbers to be added or subtracted should be aligned so that their place values coincide vertically.

In the case of decimal fractions, this rule also results in the decimal points of both the numbers being aligned vertically.

Once the numbers are aligned as above, the rules of addition & subtraction are the same as in whole numbers. The decimal point in the result will also be aligned with the decimal points of the numbers operated on.

Let us illustrate these rules by adding 267.48 & 39.56.

2 6 7 . 4 8

3 9 . 5 6

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3 0 7 . 0 4

How do we add 267.48 and 39.563?

We just add a 0 to the right of 267.48 and make it 267.480. We have seen that this does not change the value of the number in any way. Once we do this, the procedure is the same as for the previous problem.