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 8 must be multiplied to get a perfect square?
- 2.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 3.Which of these is a perfect square? (a) 484 (b) 485 (c) 525
- 4.What is the smallest whole number by which 243 must be divided to get a perfect square?
- 5.Which of these is a perfect square? (a) 357 (b) 350 (c) 324
- 6.A square garden has an area of 36 square m. How long is each side (in m)?
- 7.What is 38²? =
- 8.A square garden has an area of 3600 square m. How long is each side (in m)?
- 9.What is √169? =
- 10.What is 29²? =
- 11.Which of these is a perfect square? (a) 575 (b) 562 (c) 529
- 12.A square garden has an area of 144 square m. How long is each side (in m)?
- 13.Which of these is a perfect square? (a) 185 (b) 169 (c) 175
- 14.What is √6561? =
- 15.What is 79²? =
- 16.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 17.What is √3844? =
- 18.What is 39²? =
- 19.What is 11²? =
- 20.How many whole numbers lie between 17² and 18²?
- 21.How many whole numbers lie between 15² and 16²?
- 22.What is 66²? =
- 23.How many whole numbers lie between 27² and 28²?
- 24.A square garden has an area of 1849 square m. How long is each side (in m)?
- 25.What is 40²? =
- 26.What is 42²? =
- 27.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 28.A square garden has an area of 361 square m. How long is each side (in m)?
- 29.Which of these is a perfect square? (a) 100 (b) 106 (c) 101
- 30.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 31.What is 78²? =
- 32.What is √784? =
- 33.What is √7569? =
- 34.How many whole numbers lie between 50² and 51²?
- 35.A square garden has an area of 841 square m. How long is each side (in m)?
- 36.What is 56²? =
- 37.What is the smallest whole number by which 8 must be divided to get a perfect square?
- 38.What is √4900? =
- 39.What is √4356? =
- 40.What is √961? =
Answer key
- 2
- 900
- 484
- 3
- 324
- 6
- 1444
- 60
- 13
- 841
- 529
- 12
- 169
- 81
- 6241
- 36
- 62
- 1521
- 121
- 34
- 30
- 4356
- 54
- 43
- 1600
- 1764
- 784
- 19
- 100
- 64
- 6084
- 28
- 87
- 100
- 29
- 3136
- 2
- 70
- 66
- 31
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