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Example 11: Convert the following unlike decimals into like decimals.

36.53, 43.025, 79.7, 0.1
Solution: Here, the maximum number of digits after the decimal point in the given decimal
numbers is 3. So, we write: 36.530, 43.025, 79.700, 0.100 making the decimal places equal in all the
decimal numbers. Hence, 36.530, 43.025, 79.700, 0.100 are the like decimals.

Uses of Decimal in Real Life

We use decimals every day while dealing with money, weight, length, capacity, etc.
While converting lower units of money, length and weight to their higher units, we require to use
decimals.

Example 12: Express the following using decimals.
(a) `70 and 50 p (b) 54 m and 25 cm (c) 35 km and 450 m
(d) 31 kg and 200 g (e) 3 L and 150 mL

50
Solution: (a) `70 and 50 p = `70 + ` = `70 + `0.50 = `70.50
100
25
(b) 54 m and 25 cm = 54 m + m = 54 m + 0.25 m = 54.25 m
100
450
(c) 35 km and 450 m = 35 km + km = 35 km + 0.450 km = 35.450 km
1000
200
(d) 31 kg and 200 g = 31 kg + kg = 31 kg + 0.200 kg = 31.200 kg
1000
150
(e) 3 L and 150 mL = 3 L + L = 3.150 L
1000
Addition and Subtraction of Decimals

To add and subtract decimals, follow the following steps:

1. Align the decimal numbers according to their place value.
2. Convert unlike decimals (if any) into like decimals.

3. Place the decimal point exactly under the decimal point.
4. Add or subtract as whole numbers.
Example 13: (a) Add: 7.12, 15.004 and 9.3

(b) Subtract 48.71 from 115.106

Solution: (a) (b)
7 • 1 2 0 1 1 5 • 1 0 6
1 5 • 0 0 4 – 4 8 • 7 1 0
+ 9 • 3 0 0 6 6 • 3 9 6
3 1 • 4 2 4
Hence, the sum of 7.12, 15.004 and Hence, the difference of 48.71 and
9.3 is 31.424 115.106 is 66.396

43 Fractions and Decimals