Class 8 Maths Worksheet: Squares and Square Roots
The method (Pairs make squares): Square: n × n. Quick way: (a + b)² = a² + 2ab + b², e.g. 42² = 1600 + 160 + 4. Square root: the number that times itself gives the square; a square ending in 4 has a root ending in 2 or 8. Make a perfect square: break into primes; multiply (or divide) by the prime left without a partner. 1 + 3 + 5 + … (n odd numbers) = n². Between n² and (n + 1)² there are 2n whole numbers.
NameDateTime takenScore ___ / 40
- 1.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 2.What is √7744? =
- 3.What is 88²? =
- 4.Which of these is a perfect square? (a) 1173 (b) 1156 (c) 1211
- 5.What is 13²? =
- 6.What is √3249? =
- 7.Which of these is a perfect square? (a) 484 (b) 520 (c) 518
- 8.How many whole numbers lie between 25² and 26²?
- 9.What is √2809? =
- 10.What is the smallest whole number by which 72 must be divided to get a perfect square?
- 11.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 12.What is √1296? =
- 13.How many whole numbers lie between 31² and 32²?
- 14.How many whole numbers lie between 9² and 10²?
- 15.Which of these is a perfect square? (a) 603 (b) 576 (c) 591
- 16.What is √7056? =
- 17.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
- 18.What is √7921? =
- 19.What is 27²? =
- 20.What is the smallest whole number by which 896 must be multiplied to get a perfect square?
- 21.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 22.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 23.What is √8836? =
- 24.What is the smallest whole number by which 832 must be divided to get a perfect square?
- 25.Which of these is a perfect square? (a) 960 (b) 900 (c) 944
- 26.How many whole numbers lie between 37² and 38²?
- 27.What is 63²? =
- 28.A square garden has an area of 676 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 18 must be divided to get a perfect square?
- 30.What is √1936? =
- 31.How many whole numbers lie between 18² and 19²?
- 32.A square garden has an area of 169 square m. How long is each side (in m)?
- 33.Which of these is a perfect square? (a) 245 (b) 225 (c) 255
- 34.What is √2401? =
- 35.What is 49²? =
- 36.How many whole numbers lie between 34² and 35²?
- 37.What is the smallest whole number by which 360 must be multiplied to get a perfect square?
- 38.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 39.What is the smallest whole number by which 208 must be multiplied to get a perfect square?
- 40.What is √3600? =
Answer key
- 256
- 88
- 7744
- 1156
- 169
- 57
- 484
- 50
- 53
- 2
- 121
- 36
- 62
- 18
- 576
- 84
- 2
- 89
- 729
- 14
- 196
- 36
- 94
- 13
- 900
- 74
- 3969
- 26
- 2
- 44
- 36
- 13
- 225
- 49
- 2401
- 68
- 10
- 81
- 13
- 60
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