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.Which of these is a perfect square? (a) 498 (b) 484 (c) 528
- 2.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 3.What is √2401? =
- 4.What is the smallest whole number by which 160 must be multiplied to get a perfect square?
- 5.What is the smallest whole number by which 147 must be divided to get a perfect square?
- 6.A square garden has an area of 2809 square m. How long is each side (in m)?
- 7.What is the smallest whole number by which 1053 must be divided to get a perfect square?
- 8.Which of these is a perfect square? (a) 157 (b) 148 (c) 144
- 9.What is the smallest whole number by which 504 must be multiplied to get a perfect square?
- 10.Which of these is a perfect square? (a) 745 (b) 780 (c) 729
- 11.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 12.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 13.What is 53²? =
- 14.What is √1225? =
- 15.What is √2916? =
- 16.What is the smallest whole number by which 20 must be multiplied to get a perfect square?
- 17.What is √8100? =
- 18.What is 77²? =
- 19.What is √5625? =
- 20.What is 90²? =
- 21.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 22.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 23.What is √1936? =
- 24.A square garden has an area of 121 square m. How long is each side (in m)?
- 25.What is 60²? =
- 26.How many whole numbers lie between 9² and 10²?
- 27.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 28.A square garden has an area of 3600 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 38² and 39²?
- 30.What is √4356? =
- 31.What is √4225? =
- 32.What is 16²? =
- 33.Which of these is a perfect square? (a) 129 (b) 121 (c) 127
- 34.What is 29²? =
- 35.Which of these is a perfect square? (a) 435 (b) 400 (c) 405
- 36.Which of these is a perfect square? (a) 194 (b) 183 (c) 169
- 37.How many whole numbers lie between 8² and 9²?
- 38.Which of these is a perfect square? (a) 529 (b) 539 (c) 531
- 39.What is √324? =
- 40.What is √225? =
Answer key
- 484
- 324
- 49
- 10
- 3
- 53
- 13
- 144
- 14
- 729
- 484
- 676
- 2809
- 35
- 54
- 5
- 90
- 5929
- 75
- 8100
- 784
- 169
- 44
- 11
- 3600
- 18
- 121
- 60
- 76
- 66
- 65
- 256
- 121
- 841
- 400
- 169
- 16
- 529
- 18
- 15
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