Page 50 - Math 7

Operations on Whole Numbers

EXERCISE 3.3
General Section - Classwork
1. Let's investigate the idea from the given examples and apply it to find the
squares of the given numbers.
2
2
2
2
Example: 3 = 9 , 30 = 900, 300 = 90000, 3000 = 9000000
30 has one zero. So its square has two zeros. 300 has two zeros . So, its square
has four zeros !!
2
2
a) 4 = ........ , 40 = ........ , 400 = ........, 4000 = ........
2
2
2
2
2
2
b) 5 = ........ , 50 = ........ , 500 = ........, 5000 = ........
c) 7 = ........ , 70 = ........ , 700 = ........, 7000 = ........
2
2
2
2
d) 8 = ........ , 80 = ........ , 800 = ........, 8000 = ........
2
2
2
2
2. Let's investigate the idea from examples and apply it to find the square
roots of the given numbers.
Example : = 9 = 3, √900 = 30, √90000 = 300 , √9000000 = 3000
900 has two zeros and its square root has one zero. 90000 has four zeros and
its square root has two zeros.
a) 4 = ........ , 400 = ........ , 40000 = ........, 4000000 = ........

b) 16 = ........ , 1600 = ........ , 160000 = ........, 16000000 = ........
c) 36 = ........ , 3600 = ........ , 360000 = ........, 36000000 = ........
d) 81 = ........ , 8100 = ........ , 810000 = ........, 81000000 = ........
Creative Section - A
3. Lets find the squares of a) 45 b) 88 c) 124
4. Let's observe the example given below and learn to identify whether the given
numbers are perfect square or not.
196 By factorization of 196 = 2 × 2 × 7 × 7 = 2 × 7 2
2
As pairing of identical factor is possible, 196 is a perfect square.
216 By factorization on 216 = 2 × 2 × 2 × 3 × 3 × 3 = 2 × 2 × 3 × 3
2
2
As 2 and 3 are left unpaired, 216 is not a perfect square number.
Let's apply the above process to test whether the following numbers are perfect
squares.

a) 225 b) 392 c) 324 d) 432 e) 576
5. Let’s find the square roots of these numbers by factorization method.
a) 64 b) 100 c) 144 d) 324 e) 784 f) 1225

Vedanta Excel in Mathematics - Book 7 48 Approved by Curriculum Development Centre, Sanothimi, Bhaktapur