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.A square garden has an area of 729 square m. How long is each side (in m)?
- 2.What is 83²? =
- 3.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 4.What is 80²? =
- 5.Which of these is a perfect square? (a) 403 (b) 417 (c) 400
- 6.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 7.What is √576? =
- 8.Which of these is a perfect square? (a) 1265 (b) 1234 (c) 1225
- 9.What is 98²? =
- 10.What is the smallest whole number by which 245 must be divided to get a perfect square?
- 11.What is 29²? =
- 12.What is √441? =
- 13.What is the smallest whole number by which 250 must be divided to get a perfect square?
- 14.How many whole numbers lie between 6² and 7²?
- 15.How many whole numbers lie between 18² and 19²?
- 16.What is 87²? =
- 17.What is 86²? =
- 18.How many whole numbers lie between 39² and 40²?
- 19.A square garden has an area of 3249 square m. How long is each side (in m)?
- 20.What is 35²? =
- 21.How many whole numbers lie between 16² and 17²?
- 22.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 23.What is √8464? =
- 24.How many whole numbers lie between 25² and 26²?
- 25.How many whole numbers lie between 48² and 49²?
- 26.What is √1600? =
- 27.What is 51²? =
- 28.What is 57²? =
- 29.What is 49²? =
- 30.What is 31²? =
- 31.How many whole numbers lie between 17² and 18²?
- 32.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 33.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 34.Which of these is a perfect square? (a) 1082 (b) 1059 (c) 1024
- 35.What is the smallest whole number by which 468 must be divided to get a perfect square?
- 36.A square garden has an area of 225 square m. How long is each side (in m)?
- 37.What is 22²? =
- 38.How many whole numbers lie between 45² and 46²?
- 39.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
- 40.How many whole numbers lie between 5² and 6²?
Answer key
- 27
- 6889
- 81
- 6400
- 400
- 441
- 24
- 1225
- 9604
- 5
- 841
- 21
- 10
- 12
- 36
- 7569
- 7396
- 78
- 57
- 1225
- 32
- 36
- 92
- 50
- 96
- 40
- 2601
- 3249
- 2401
- 961
- 34
- 3
- 144
- 1024
- 13
- 15
- 484
- 90
- 2
- 10
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