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 252 must be divided to get a perfect square?
- 2.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 3.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 4.What is 31²? =
- 5.What is 58²? =
- 6.How many whole numbers lie between 34² and 35²?
- 7.What is 19²? =
- 8.What is √3136? =
- 9.A square garden has an area of 1089 square m. How long is each side (in m)?
- 10.Which of these is a perfect square? (a) 790 (b) 784 (c) 804
- 11.How many whole numbers lie between 29² and 30²?
- 12.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 13.What is the smallest whole number by which 63 must be multiplied to get a perfect square?
- 14.What is 81²? =
- 15.What is √4225? =
- 16.A square garden has an area of 2401 square m. How long is each side (in m)?
- 17.What is √400? =
- 18.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 19.What is 18²? =
- 20.Which of these is a perfect square? (a) 694 (b) 709 (c) 676
- 21.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 22.What is the smallest whole number by which 192 must be multiplied to get a perfect square?
- 23.What is √4489? =
- 24.What is √3364? =
- 25.What is the smallest whole number by which 360 must be divided to get a perfect square?
- 26.Which of these is a perfect square? (a) 900 (b) 950 (c) 920
- 27.What is √4761? =
- 28.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 29.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 30.What is 24²? =
- 31.What is √1849? =
- 32.How many whole numbers lie between 22² and 23²?
- 33.Which of these is a perfect square? (a) 1107 (b) 1089 (c) 1108
- 34.What is the smallest whole number by which 832 must be multiplied to get a perfect square?
- 35.How many whole numbers lie between 18² and 19²?
- 36.How many whole numbers lie between 26² and 27²?
- 37.How many whole numbers lie between 27² and 28²?
- 38.What is 60²? =
- 39.A square garden has an area of 36 square m. How long is each side (in m)?
- 40.What is 75²? =
Answer key
- 7
- 256
- 729
- 961
- 3364
- 68
- 361
- 56
- 33
- 784
- 58
- 100
- 7
- 6561
- 65
- 49
- 20
- 576
- 324
- 676
- 529
- 3
- 67
- 58
- 10
- 900
- 69
- 484
- 784
- 576
- 43
- 44
- 1089
- 13
- 36
- 52
- 54
- 3600
- 6
- 5625
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