Page 71 - Start Up Mathematics_8 (Non CCE)

2. The smallest number by which 98 must be divided to make it a perfect square is:
(a) 2 (b) 3 (c) 7 (d) 6
3. The square root of 12345654321 is:
(a) 11,111 (b) 10,101 (c) 1,11,111 (d) 1,01,01,101

4. 0.09 is equal to:
(a) 0.03 (b) 0.3 (c) 0.003 (d) 0.034
5. The smallest number that must be subtracted from 176 to make it a perfect square is:
(a) 16 (b) 7 (c) 10 (d) 4

6. 7225 is equal to:
(a) 75 (b) 85 (c) 65 (d) 95

solve Mentally

True or False

1. The square of an odd number is always odd.
2. The sum or difference of two square numbers is a square number.
2
3. (93) = 8,649
1
4. The value of ¥ 5.76 is 7.
0.09

5. For positive numbers x and y, x ¥ y = xy .
Fill in the Blanks

1. A number ending in 2, 3, 7 or 8 is ______________ a perfect square.
2. On dividing a perfect square by 4, the remainder is ___________ or ______________.
3. A number ending in ______________ number of zeros is never a perfect square.
4. (3, 4, 5) is a ______________.
2
5. (115) = ______________.
6. 9,99,98,00,001 = ______________.
7. Calculate mentally the sum of 1 + 3 + 5 + 7 + 9 + 11 + 13 = ______________.
2
2
8. The value of 100 – 99 is __________________.
Answer in One Word or a Line
1. Define perfect squares.
2. What is a Pythagorean triplet? Is 32,255,257 a Pythagorean triplet?
3. In the system of rational numbers, which numbers do not have square roots?
4. Is the sum or difference of two square numbers always a square number? Justify your answer with an
example.

let’s evaluate

1. Which of the following are perfect squares?
(a) 7,921 (b) 4,638 (c) 3,844
2
2
2
2
2
2. Using a suitable property evaluate: (a) 35 – 34 (b) 62 – 61 (c) 153 – 152 2
3. Find the squares using the column method: (a) 68 (b) 34 (c) 92
4. Find the squares using the diagonal method: (a) 97 (b) 59 (c) 28
5. Find the square root using the prime factorization method: (a) 4,624 (b) 3,600 (c) 7,921
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