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.How many whole numbers lie between 35² and 36²?
- 2.Which of these is a perfect square? (a) 188 (b) 180 (c) 169
- 3.What is the smallest whole number by which 160 must be multiplied to get a perfect square?
- 4.How many whole numbers lie between 16² and 17²?
- 5.What is the smallest whole number by which 637 must be multiplied to get a perfect square?
- 6.What is √1089? =
- 7.What is √1296? =
- 8.What is √961? =
- 9.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 10.Which of these is a perfect square? (a) 1062 (b) 1086 (c) 1024
- 11.A square garden has an area of 81 square m. How long is each side (in m)?
- 12.What is 75²? =
- 13.How many whole numbers lie between 43² and 44²?
- 14.What is √6400? =
- 15.What is √576? =
- 16.How many whole numbers lie between 45² and 46²?
- 17.What is √4900? =
- 18.Which of these is a perfect square? (a) 144 (b) 167 (c) 147
- 19.How many whole numbers lie between 6² and 7²?
- 20.A square garden has an area of 1521 square m. How long is each side (in m)?
- 21.What is 57²? =
- 22.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 23.What is √1024? =
- 24.What is 14²? =
- 25.A square garden has an area of 144 square m. How long is each side (in m)?
- 26.What is the smallest whole number by which 891 must be divided to get a perfect square?
- 27.What is 71²? =
- 28.A square garden has an area of 3249 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 832 must be divided to get a perfect square?
- 30.What is √1600? =
- 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 18 must be divided to get a perfect square?
- 33.What is √6084? =
- 34.A square garden has an area of 196 square m. How long is each side (in m)?
- 35.A square garden has an area of 36 square m. How long is each side (in m)?
- 36.How many whole numbers lie between 39² and 40²?
- 37.What is 76²? =
- 38.What is 20²? =
- 39.Which of these is a perfect square? (a) 378 (b) 361 (c) 374
- 40.What is √2025? =
Answer key
- 70
- 169
- 10
- 32
- 13
- 33
- 36
- 31
- 441
- 1024
- 9
- 5625
- 86
- 80
- 24
- 90
- 70
- 144
- 12
- 39
- 3249
- 625
- 32
- 196
- 12
- 11
- 5041
- 57
- 13
- 40
- 46
- 2
- 78
- 14
- 6
- 78
- 5776
- 400
- 361
- 45
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