Page 113 - New Medley 4 Semester 1

Rounding Off Numbers

A camera is priced `24058.

A customer asked the salesman ‘How much will this cost?’

Our salesman replies “nearly 24000.”

Z Z Many times we don’t have or we don’t require the exact number.

Z Z To get the idea of the number we round the number.

Z Z This rounding may be to the nearest tens, hundreds, thousands, ten
thousands, etc.

Rounding to the Nearest Tens

Rule 1: If the digit in the units place is 0 or 1 or 2 or 3 or 4 (less than
5) then we make the units place 0.

Rule 2: If the digit in the units place is 5 or 6 or 7 or 8 or 9 (more

than or equal to 5) then we make the units place zero and add
10 to the number.

Example 29: Round the following numbers to the nearest tens
(a) 38964 (b) 484176

Solution: (a) Unit’s digit of 38964 is 4. Clearly rule 1 is applicable.

To round the number to the nearest 10 we replace 4
by 0.

Hence 38964 rounded to the nearest ten is 38960.

(b) Unit’s digit of 484176 is 6. Clearly rule 2 is applicable.

To round the number to the nearest 10 we replace 6 by

0 and add 10.

484170 + 10 = 484180

Hence 484176 rounded to the nearest ten is 484180.

Rounding to the Nearest Hundreds

Rule 1: If the digit in the tens place is 0 or 1 or 2 or 3 or 4 (less than 5)
then we make the tens and the units place both as zero.

111