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 91²? =
- 2.Which of these is a perfect square? (a) 389 (b) 397 (c) 361
- 3.What is 67²? =
- 4.Which of these is a perfect square? (a) 1269 (b) 1294 (c) 1225
- 5.What is 21²? =
- 6.What is the smallest whole number by which 98 must be divided to get a perfect square?
- 7.What is the smallest whole number by which 56 must be multiplied to get a perfect square?
- 8.Which of these is a perfect square? (a) 242 (b) 252 (c) 225
- 9.What is √784? =
- 10.How many whole numbers lie between 25² and 26²?
- 11.What is √225? =
- 12.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 13.What is √3136? =
- 14.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 15.What is 84²? =
- 16.A square garden has an area of 36 square m. How long is each side (in m)?
- 17.What is √4489? =
- 18.Which of these is a perfect square? (a) 289 (b) 294 (c) 315
- 19.A square garden has an area of 484 square m. How long is each side (in m)?
- 20.What is √961? =
- 21.What is 97²? =
- 22.How many whole numbers lie between 39² and 40²?
- 23.What is √5329? =
- 24.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 25.What is √4624? =
- 26.What is the smallest whole number by which 117 must be divided to get a perfect square?
- 27.How many whole numbers lie between 34² and 35²?
- 28.A square garden has an area of 196 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 38² and 39²?
- 30.What is the smallest whole number by which 891 must be divided to get a perfect square?
- 31.What is the smallest whole number by which 350 must be divided to get a perfect square?
- 32.Which of these is a perfect square? (a) 144 (b) 152 (c) 149
- 33.A square garden has an area of 144 square m. How long is each side (in m)?
- 34.A square garden has an area of 25 square m. How long is each side (in m)?
- 35.A square garden has an area of 529 square m. How long is each side (in m)?
- 36.What is 64²? =
- 37.What is 77²? =
- 38.What is the smallest whole number by which 243 must be divided to get a perfect square?
- 39.A square garden has an area of 1296 square m. How long is each side (in m)?
- 40.How many whole numbers lie between 5² and 6²?
Answer key
- 8281
- 361
- 4489
- 1225
- 441
- 2
- 14
- 225
- 28
- 50
- 15
- 324
- 56
- 900
- 7056
- 6
- 67
- 289
- 22
- 31
- 9409
- 78
- 73
- 49
- 68
- 13
- 68
- 14
- 76
- 11
- 14
- 144
- 12
- 5
- 23
- 4096
- 5929
- 3
- 36
- 10
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