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 √2401? =
- 2.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 3.What is √3364? =
- 4.What is 33²? =
- 5.Which of these is a perfect square? (a) 1600 (b) 1646 (c) 1655
- 6.Which of these is a perfect square? (a) 140 (b) 121 (c) 130
- 7.Which of these is a perfect square? (a) 961 (b) 994 (c) 1004
- 8.A square garden has an area of 256 square m. How long is each side (in m)?
- 9.What is the smallest whole number by which 108 must be multiplied to get a perfect square?
- 10.How many whole numbers lie between 15² and 16²?
- 11.What is 84²? =
- 12.What is the smallest whole number by which 99 must be divided to get a perfect square?
- 13.How many whole numbers lie between 9² and 10²?
- 14.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 15.What is the smallest whole number by which 8 must be multiplied to get a perfect square?
- 16.Which of these is a perfect square? (a) 165 (b) 160 (c) 144
- 17.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 18.What is √1225? =
- 19.Which of these is a perfect square? (a) 576 (b) 610 (c) 585
- 20.What is √4489? =
- 21.How many whole numbers lie between 44² and 45²?
- 22.What is 11²? =
- 23.What is √2809? =
- 24.A square garden has an area of 49 square m. How long is each side (in m)?
- 25.What is √196? =
- 26.A square garden has an area of 121 square m. How long is each side (in m)?
- 27.What is √1024? =
- 28.What is the smallest whole number by which 832 must be multiplied to get a perfect square?
- 29.Which of these is a perfect square? (a) 1402 (b) 1391 (c) 1369
- 30.How many whole numbers lie between 27² and 28²?
- 31.What is √6561? =
- 32.A square garden has an area of 1521 square m. How long is each side (in m)?
- 33.What is the smallest whole number by which 180 must be multiplied to get a perfect square?
- 34.What is √9216? =
- 35.What is the smallest whole number by which 1053 must be multiplied to get a perfect square?
- 36.What is 66²? =
- 37.What is 96²? =
- 38.What is √6400? =
- 39.Which of these is a perfect square? (a) 551 (b) 542 (c) 529
- 40.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
Answer key
- 49
- 169
- 58
- 1089
- 1600
- 121
- 961
- 16
- 3
- 30
- 7056
- 11
- 18
- 36
- 2
- 144
- 676
- 35
- 576
- 67
- 88
- 121
- 53
- 7
- 14
- 11
- 32
- 13
- 1369
- 54
- 81
- 39
- 5
- 96
- 13
- 4356
- 9216
- 80
- 529
- 441
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