Page 52 - ICSE Math 8

3
Example 24: Find the square root of (a) 436.23 and (b) 12 upto two decimal places.
4
3 51
Solution: (a) Add 4 zeros after the decimal part to (b) 12 = = 12.75
form 3 decimal places. 4 4

20.886 3.5707
2 4 36. 23 00 00 3 12.75 00 00 00
4 9
40 36 65 375
00 325
408 36 23 707 5000
32 64 4949
4168 3 5900 7140 510000
3 3344 499849
41766 255600 10151
250596
5004 \ 12.75 = 3.5707 ª 3.57 correct upto
2 decimal places.
\ 436.23 ≈ 20.886 or 20.89 correct
upto 2 decimal places.

225
Example 25: Given 2 = 1.41 and 3 = 1.73, evaluate .
1,014

225 225 15 15 15 6
Solution: = = = = ×
1,014 169 6× 169 × 6 13 6 13 6 6

15 × 6 5 × 23 5 × 2 × 3
×
= = =
13 6 13 2 26
×
×
5 1.41 1.73× × 12.1965
= = = 0.47
26 26
EXERCISE 3.7

1. Find the square root of the following correct upto two decimal places.
(a) 11 (b) 76 (c) 111 (d) 437.06 (e) 38.04 (f) 7.8

2. Given 2 = 1.41, 3 = 1.73, 5 = 2.23, evaluate the following.

361 3,136 5,625
(a) (b) (c) (d) 5,000
5 15 6

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3. The area of a square field is 425.31 m . Find the length of the side of the field upto three decimal places.
2 2
4. Find the square root of upto 2 decimal places. (Hint: Convert to a decimal number)
3 3

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