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 6 odd numbers (1 + 3 + 5 + …)?
- 2.Which of these is a perfect square? (a) 484 (b) 494 (c) 490
- 3.How many whole numbers lie between 14² and 15²?
- 4.What is √2601? =
- 5.How many whole numbers lie between 27² and 28²?
- 6.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 7.Which of these is a perfect square? (a) 1309 (b) 1316 (c) 1296
- 8.What is 56²? =
- 9.What is 28²? =
- 10.What is √2304? =
- 11.Which of these is a perfect square? (a) 270 (b) 256 (c) 271
- 12.What is the smallest whole number by which 108 must be divided to get a perfect square?
- 13.A square garden has an area of 1936 square m. How long is each side (in m)?
- 14.How many whole numbers lie between 12² and 13²?
- 15.Which of these is a perfect square? (a) 807 (b) 810 (c) 784
- 16.How many whole numbers lie between 41² and 42²?
- 17.Which of these is a perfect square? (a) 136 (b) 128 (c) 121
- 18.What is √6400? =
- 19.What is 99²? =
- 20.What is the smallest whole number by which 48 must be divided to get a perfect square?
- 21.What is 59²? =
- 22.What is √1764? =
- 23.What is 53²? =
- 24.How many whole numbers lie between 10² and 11²?
- 25.How many whole numbers lie between 40² and 41²?
- 26.What is the smallest whole number by which 60 must be multiplied to get a perfect square?
- 27.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 28.What is 81²? =
- 29.What is √2116? =
- 30.What is the smallest whole number by which 90 must be multiplied to get a perfect square?
- 31.How many whole numbers lie between 39² and 40²?
- 32.What is 25²? =
- 33.A square garden has an area of 36 square m. How long is each side (in m)?
- 34.How many whole numbers lie between 45² and 46²?
- 35.A square garden has an area of 1156 square m. How long is each side (in m)?
- 36.How many whole numbers lie between 17² and 18²?
- 37.How many whole numbers lie between 20² and 21²?
- 38.Which of these is a perfect square? (a) 667 (b) 646 (c) 625
- 39.A square garden has an area of 961 square m. How long is each side (in m)?
- 40.Which of these is a perfect square? (a) 1093 (b) 1089 (c) 1096
Answer key
- 36
- 484
- 28
- 51
- 54
- 144
- 1296
- 3136
- 784
- 48
- 256
- 3
- 44
- 24
- 784
- 82
- 121
- 80
- 9801
- 3
- 3481
- 42
- 2809
- 20
- 80
- 15
- 361
- 6561
- 46
- 10
- 78
- 625
- 6
- 90
- 34
- 34
- 40
- 625
- 31
- 1089
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