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 8 must be multiplied to get a perfect square?
- 2.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 3.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 4.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 5.How many whole numbers lie between 16² and 17²?
- 6.What is 84²? =
- 7.Which of these is a perfect square? (a) 590 (b) 603 (c) 576
- 8.What is 76²? =
- 9.What is 57²? =
- 10.A square garden has an area of 2916 square m. How long is each side (in m)?
- 11.What is 33²? =
- 12.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 13.What is 55²? =
- 14.Which of these is a perfect square? (a) 502 (b) 484 (c) 495
- 15.What is 99²? =
- 16.How many whole numbers lie between 25² and 26²?
- 17.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 18.Which of these is a perfect square? (a) 225 (b) 252 (c) 254
- 19.A square garden has an area of 625 square m. How long is each side (in m)?
- 20.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 21.What is 64²? =
- 22.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
- 23.Which of these is a perfect square? (a) 263 (b) 256 (c) 258
- 24.How many whole numbers lie between 22² and 23²?
- 25.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 26.What is 62²? =
- 27.A square garden has an area of 1089 square m. How long is each side (in m)?
- 28.How many whole numbers lie between 12² and 13²?
- 29.What is √7744? =
- 30.What is 27²? =
- 31.A square garden has an area of 2601 square m. How long is each side (in m)?
- 32.What is the smallest whole number by which 48 must be divided to get a perfect square?
- 33.A square garden has an area of 121 square m. How long is each side (in m)?
- 34.How many whole numbers lie between 34² and 35²?
- 35.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 36.How many whole numbers lie between 5² and 6²?
- 37.What is 38²? =
- 38.How many whole numbers lie between 13² and 14²?
- 39.How many whole numbers lie between 32² and 33²?
- 40.Which of these is a perfect square? (a) 1448 (b) 1485 (c) 1444
Answer key
- 2
- 784
- 625
- 900
- 32
- 7056
- 576
- 5776
- 3249
- 54
- 1089
- 100
- 3025
- 484
- 9801
- 50
- 841
- 225
- 25
- 225
- 4096
- 2
- 256
- 44
- 144
- 3844
- 33
- 24
- 88
- 729
- 51
- 3
- 11
- 68
- 289
- 10
- 1444
- 26
- 64
- 1444
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