Page 100 - Start Up Mathematics_5

Comparison of Decimal Numbers

To compare decimal numbers follow the given steps.

Step 1: Change unlike decimals to like decimals.
Step 2: First compare the integral part. The decimal number with a greater integral part is
greater.

Step 3: If the integral part is equal, then compare the tenths digit. The decimal number with
greater tenths digit is greater.

Step 4: If the integral part and the tenths digit are same, compare the hundredths digits.
Step 5: If the integral part, the tenths digit and the hundredths digit are same, compare
the thousandths digit.

Example 5: Compare 33.15 and 33.8.

Solution: 33.8 = 33.80 (converting 33.8 to like decimal)
The integral part of both decimal numbers is the same. So, we compare the
tenths digits.
Since 1 < 8, so 33.15 < 33.80.

Example 6: Arrange the following decimal numbers in ascending order.

7.284, 7.14, 7.03, 7.9, 7.015
Solution: First change the unlike decimal numbers to like decimal numbers.

7.284 = 7.284, 7.14 = 7.140, 7.03 = 7.030, 7.9 = 7.900, 7.015 = 7.015
The integral part of each decimal number is the same. So, we compare the
decimal part.
7.015 < 7.030 < 7.140 < 7.284 < 7.900

7.015, 7.030, 7.140, 7.284, 7.900 is the required ascending order.
Example 7: Arrange the following decimal numbers in descending order.

23.15, 22.98, 23.618, 22.045, 23.07

Solution: Change the unlike decimals to like decimals.
23.15 = 23.150, 22.98 = 22.980, 23.618 = 23.618, 22.045 = 22.045, 23.07 = 23.070
Compare the integral and the decimal part.

23.618, 23.150, 23.070, 22.980, 22.045 is the required descending order.

EXERCISE 6.4

1. Arrange the following decimal numbers in ascending order.
(a) 16.34, 5.34, 29.34, 2.34, 21.34 (b) 8.062, 8.62, 8.006, 8.02, 8.206

(c) 50.27, 50.981, 48.06, 47.245, 45.16 (d) 21.5, 26.04, 22.8, 21.49, 22.03

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