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 40 must be multiplied to get a perfect square?
- 2.A square garden has an area of 729 square m. How long is each side (in m)?
- 3.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 4.How many whole numbers lie between 6² and 7²?
- 5.What is √6241? =
- 6.Which of these is a perfect square? (a) 1119 (b) 1122 (c) 1089
- 7.How many whole numbers lie between 26² and 27²?
- 8.How many whole numbers lie between 42² and 43²?
- 9.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 10.What is 48²? =
- 11.What is √841? =
- 12.How many whole numbers lie between 50² and 51²?
- 13.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 14.Which of these is a perfect square? (a) 1453 (b) 1444 (c) 1501
- 15.What is 90²? =
- 16.A square garden has an area of 441 square m. How long is each side (in m)?
- 17.What is the smallest whole number by which 891 must be divided to get a perfect square?
- 18.How many whole numbers lie between 33² and 34²?
- 19.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 20.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 21.What is √2809? =
- 22.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 23.What is √289? =
- 24.How many whole numbers lie between 21² and 22²?
- 25.What is 17²? =
- 26.What is the smallest whole number by which 468 must be multiplied to get a perfect square?
- 27.What is the smallest whole number by which 384 must be multiplied to get a perfect square?
- 28.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 29.What is √1296? =
- 30.How many whole numbers lie between 40² and 41²?
- 31.How many whole numbers lie between 13² and 14²?
- 32.Which of these is a perfect square? (a) 646 (b) 625 (c) 652
- 33.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 34.How many whole numbers lie between 5² and 6²?
- 35.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 36.What is √4624? =
- 37.What is √4900? =
- 38.What is √3600? =
- 39.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 40.A square garden has an area of 2116 square m. How long is each side (in m)?
Answer key
- 10
- 27
- 289
- 12
- 79
- 1089
- 52
- 84
- 225
- 2304
- 29
- 100
- 36
- 1444
- 8100
- 21
- 11
- 66
- 400
- 529
- 53
- 121
- 17
- 42
- 289
- 13
- 6
- 484
- 36
- 80
- 26
- 625
- 361
- 10
- 81
- 68
- 70
- 60
- 256
- 46
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