We will discuss here about the addition of decimals. Decimals are added in the same way as we add ordinary numbers. We arrange the digits in columns and then add as required.

Let us consider some of the following examples on adding decimals.

1. Add 3.4, 4.6 and 5.2

 Step I: Write the numbers vertically aligning on the decimal points.Add the tenths.4 + 6 + 2 = 12Place 2 in the tenths column and place the point before it. Carry 1 to the whole number part.Add the whole numbers.3 + 4 + 5 + 1 = 13The sum of 3.4, 4.6 and 5.2 is 13.2 The required sum is 13.2

2. Add 14.539, 5 and 3.8

 Step I:Write the numbers vertically aligning on the decimal points.Write equivalent decimals of 5 and 3.8 up to three places.5 = 5.000                      3.8 = 3.800Add thousandths9 + 0 + 0 = 9. Write 9 under thousandthsAdd hundredths3 + 0 + 0 = 3. Write 3 under hundredths Add tenths5 + 0 + 8 = 13. Write 3 under tenths and carry 1 to ones place.Add ones.4 + 5 + 3 + 1 = 13. Write 3 under ones and carry 1 to tens place. Add tens.1 + 1 = 2. Write 2 under tens. The required sum is 23.339

3. Add 46.25, 108.45 and 456.62

We arrange the digits of decimals in columns and then we add the numbers as usual.

 4 6 . 2 5               1 0 8 . 4 5           +  4 5 6 . 6 2               6 1 1 . 3 2 While adding we ensure that the decimal point of all the numbers should be in the same column.

Sometimes the numbers to be added may not have digits for each column. In such case, we can add zero at the extreme right or left of a given decimal number.

4. Add 230.45, 189.568 and 25.709

Here we will see adding decimals in two ways. We arrange the digits of decimals in columns and then we add the numbers as usual.

 2 3 0 . 4 5        1 8 9 . 5 6 8      +   2 5 . 7 0 9         4 4 5 . 7 2 7 Or, 2 3 0 . 4 5 0        1 8 9 . 5 6 8     + 0 2 5 . 7 0 9        4 4 5 . 7 2 7

(i) 7.9 + 2.8 + 3.2 + 16.8 = ..............

(ii) 83.1 + 18.2 + 45.4 + 14.7 = ..............

(iii) 24.35 + 19.10 + 28.39 + 5.40 = ..............

(iv) 10.00 + 1.05 + 2.30 + 8.75 = ..............

I. (i) 30.70

(ii) 161.40

(iii) 77.24

(iv) 22.10