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 20²? =
- 2.Which of these is a perfect square? (a) 1156 (b) 1201 (c) 1210
- 3.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
- 4.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 5.What is 52²? =
- 6.What is the smallest whole number by which 637 must be multiplied to get a perfect square?
- 7.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 8.What is 58²? =
- 9.What is √1521? =
- 10.How many whole numbers lie between 16² and 17²?
- 11.What is 97²? =
- 12.Which of these is a perfect square? (a) 248 (b) 236 (c) 225
- 13.What is 83²? =
- 14.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 15.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 16.What is √400? =
- 17.What is 25²? =
- 18.How many whole numbers lie between 46² and 47²?
- 19.What is 29²? =
- 20.What is √6400? =
- 21.A square garden has an area of 324 square m. How long is each side (in m)?
- 22.What is 66²? =
- 23.How many whole numbers lie between 35² and 36²?
- 24.What is 85²? =
- 25.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 26.What is 30²? =
- 27.What is √1225? =
- 28.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 29.What is √5041? =
- 30.What is 86²? =
- 31.How many whole numbers lie between 40² and 41²?
- 32.How many whole numbers lie between 49² and 50²?
- 33.What is the smallest whole number by which 810 must be multiplied to get a perfect square?
- 34.A square garden has an area of 196 square m. How long is each side (in m)?
- 35.Which of these is a perfect square? (a) 574 (b) 529 (c) 547
- 36.What is 18²? =
- 37.What is 94²? =
- 38.How many whole numbers lie between 5² and 6²?
- 39.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 40.A square garden has an area of 144 square m. How long is each side (in m)?
Answer key
- 400
- 1156
- 3
- 900
- 2704
- 13
- 49
- 3364
- 39
- 32
- 9409
- 225
- 6889
- 25
- 81
- 20
- 625
- 92
- 841
- 80
- 18
- 4356
- 70
- 7225
- 225
- 900
- 35
- 324
- 71
- 7396
- 80
- 98
- 10
- 14
- 529
- 324
- 8836
- 10
- 289
- 12
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