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 sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 2.What is √3136? =
- 3.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 4.Which of these is a perfect square? (a) 1631 (b) 1643 (c) 1600
- 5.What is 50²? =
- 6.What is √3025? =
- 7.A square garden has an area of 1936 square m. How long is each side (in m)?
- 8.How many whole numbers lie between 18² and 19²?
- 9.Which of these is a perfect square? (a) 1003 (b) 1016 (c) 961
- 10.Which of these is a perfect square? (a) 100 (b) 106 (c) 117
- 11.What is 22²? =
- 12.A square garden has an area of 841 square m. How long is each side (in m)?
- 13.What is 75²? =
- 14.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 15.What is √5776? =
- 16.What is the smallest whole number by which 40 must be multiplied to get a perfect square?
- 17.How many whole numbers lie between 43² and 44²?
- 18.What is √1024? =
- 19.Which of these is a perfect square? (a) 292 (b) 289 (c) 312
- 20.A square garden has an area of 1849 square m. How long is each side (in m)?
- 21.What is √3721? =
- 22.Which of these is a perfect square? (a) 359 (b) 324 (c) 356
- 23.A square garden has an area of 1444 square m. How long is each side (in m)?
- 24.What is the smallest whole number by which 18 must be divided to get a perfect square?
- 25.What is 37²? =
- 26.Which of these is a perfect square? (a) 121 (b) 122 (c) 137
- 27.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
- 28.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 29.Which of these is a perfect square? (a) 511 (b) 497 (c) 484
- 30.What is 70²? =
- 31.How many whole numbers lie between 48² and 49²?
- 32.How many whole numbers lie between 44² and 45²?
- 33.What is √9604? =
- 34.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 35.A square garden has an area of 2116 square m. How long is each side (in m)?
- 36.What is √225? =
- 37.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 38.How many whole numbers lie between 23² and 24²?
- 39.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 40.What is √4489? =
Answer key
- 324
- 56
- 841
- 1600
- 2500
- 55
- 44
- 36
- 961
- 100
- 484
- 29
- 5625
- 529
- 76
- 10
- 86
- 32
- 289
- 43
- 61
- 324
- 38
- 2
- 1369
- 121
- 2
- 441
- 484
- 4900
- 96
- 88
- 98
- 256
- 46
- 15
- 400
- 46
- 3
- 67
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