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 smallest whole number by which 80 must be multiplied to get a perfect square?
- 2.A square garden has an area of 3136 square m. How long is each side (in m)?
- 3.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 4.Which of these is a perfect square? (a) 1497 (b) 1444 (c) 1479
- 5.A square garden has an area of 400 square m. How long is each side (in m)?
- 6.How many whole numbers lie between 7² and 8²?
- 7.What is 73²? =
- 8.How many whole numbers lie between 27² and 28²?
- 9.What is the smallest whole number by which 150 must be multiplied to get a perfect square?
- 10.How many whole numbers lie between 9² and 10²?
- 11.What is √8281? =
- 12.What is 55²? =
- 13.What is √121? =
- 14.How many whole numbers lie between 47² and 48²?
- 15.A square garden has an area of 841 square m. How long is each side (in m)?
- 16.What is 58²? =
- 17.What is 27²? =
- 18.A square garden has an area of 3025 square m. How long is each side (in m)?
- 19.What is 26²? =
- 20.Which of these is a perfect square? (a) 334 (b) 340 (c) 324
- 21.A square garden has an area of 2809 square m. How long is each side (in m)?
- 22.Which of these is a perfect square? (a) 817 (b) 828 (c) 784
- 23.What is 86²? =
- 24.What is the smallest whole number by which 72 must be divided to get a perfect square?
- 25.What is the smallest whole number by which 405 must be divided to get a perfect square?
- 26.What is √400? =
- 27.What is 15²? =
- 28.A square garden has an area of 49 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 41² and 42²?
- 30.What is 62²? =
- 31.A square garden has an area of 2116 square m. How long is each side (in m)?
- 32.What is the smallest whole number by which 54 must be multiplied to get a perfect square?
- 33.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 34.How many whole numbers lie between 14² and 15²?
- 35.What is √529? =
- 36.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 37.Which of these is a perfect square? (a) 846 (b) 841 (c) 884
- 38.A square garden has an area of 676 square m. How long is each side (in m)?
- 39.Which of these is a perfect square? (a) 614 (b) 613 (c) 576
- 40.How many whole numbers lie between 17² and 18²?
Answer key
- 5
- 56
- 841
- 1444
- 20
- 14
- 5329
- 54
- 6
- 18
- 91
- 3025
- 11
- 94
- 29
- 3364
- 729
- 55
- 676
- 324
- 53
- 784
- 7396
- 2
- 5
- 20
- 225
- 7
- 82
- 3844
- 46
- 6
- 49
- 28
- 23
- 25
- 841
- 26
- 576
- 34
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