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\ 11-Sep-2024 Sonia Suyal Proof-1 Reader’s Sign _______________________ Date __________

Practice time 1e

1. Complete the following table.

Predecessor Number Successor
(a) 5,672
(b) 8,791
(c) 998
(d) 4,041

2. Identify even numbers and odd numbers in the following numbers.

2,371 4,628 7,132 8,903 3,925 6,000 8,143
9,465 3,784 5,828 1,116 1,358 2,047 9,999
3. Write the even numbers that come between:

(a) 402 and 409 (b) 1,023 and 1,029 (c) 2,448 and 2,456

4. Write the odd numbers that come between:
(a) 111 and 119 (b) 1,031 and 1,038 (c) 4,444 and 4,450

rouNDiNg oFF Numbers

Look at the following statements.
1. About 1500 people came for the annual day function.

2. Approximately, 250 athletes participated in the marathon.
3. Approximate cost of a toy car is `100.

In such cases, the number gives an approximate idea which is close enough to the exact
number or amount.

This approximate value may be slightly greater or lesser than the actual value.

To find an approximate value is known as estimation. This is done by rounding off the
number nearest to tens, hundreds, and so on.
rounding off a number to the nearest ten

Let us see how to round off a number to the nearest 10.
example 1: Round off 33 to the nearest 10.

Solution: First of all, identify the two tens
between which 33 falls. The two 30 31 32 33 34 35 36 37 38 39 40

tens are 30 and 40. Draw a number line showing the numbers 30 to 40.
Looking at the number line, it is clear that 33 is closer to 30 than to 40.

So, 33 is rounded down to 30.

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