Page 47 - Math 7

Operations on Whole Numbers

2 645 16 254 The greatest perfect square less than 6 is 4
and its square root is 2.
+ 2 – 4
24 ÷ 4 = 6, 46 × 6 = 276 > 245
45 245 so, 45 × 5 = 225
+ 5 –225
504 2016 20 ÷ 5 = 4 , 504 × 4 = 2016.
+ 4 –2016

508 0
Worked out examples

Example 1: Find the square of a) 24 b) 85 c) 120

Solution:
a) Square of 24 = 24 = 24 × 24 = 576
2
2
b) Square of 85 = 85 = 85 × 85 = 7225
2
c) Square of 120 = 120 = 120 × 120 = 144000 12×12 = 144, then 120×120=14400
Example 2: Find the square root of 1764 by prime factorisation method.
f
Solution: I got it!
2 1764 Now, 1764 = 2 u 2 u 3 u 3 u 7 u 7 The product of one of the
2 882 identical factors taken from
2
2
3 441 = 2 u 3 u 7 2 each pair is the square root.
3 147 ? 1764 = 2 u 3 u 7 = 42
7 49
7

Example 3: Find the square root of 11449 by division method.

Solution:
1 114 49 107
+ 1 –1

20 14 While making the number pairs in
+ 0 –0 11449 from the unit place, 1 is left
unpaired. So, it is divided at first.
207 1449
+ 7 –1449
214 0

? 11449 = 107

Approved by Curriculum Development Centre, Sanothimi, Bhaktapur 45 Vedanta Excel in Mathematics - Book 7