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) 900 (b) 930 (c) 912
- 2.What is 32²? =
- 3.How many whole numbers lie between 15² and 16²?
- 4.What is 59²? =
- 5.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 6.What is √2601? =
- 7.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 8.What is √441? =
- 9.How many whole numbers lie between 20² and 21²?
- 10.What is √1936? =
- 11.How many whole numbers lie between 17² and 18²?
- 12.What is √2500? =
- 13.What is √8649? =
- 14.A square garden has an area of 2209 square m. How long is each side (in m)?
- 15.What is the smallest whole number by which 320 must be multiplied to get a perfect square?
- 16.What is the smallest whole number by which 99 must be divided to get a perfect square?
- 17.A square garden has an area of 3600 square m. How long is each side (in m)?
- 18.What is √4356? =
- 19.What is the smallest whole number by which 27 must be multiplied to get a perfect square?
- 20.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 21.What is the smallest whole number by which 320 must be divided to get a perfect square?
- 22.Which of these is a perfect square? (a) 824 (b) 784 (c) 787
- 23.What is the smallest whole number by which 640 must be multiplied to get a perfect square?
- 24.A square garden has an area of 289 square m. How long is each side (in m)?
- 25.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 26.What is the smallest whole number by which 52 must be divided to get a perfect square?
- 27.How many whole numbers lie between 13² and 14²?
- 28.What is √6241? =
- 29.What is the smallest whole number by which 1053 must be divided to get a perfect square?
- 30.Which of these is a perfect square? (a) 274 (b) 259 (c) 256
- 31.What is the smallest whole number by which 150 must be divided to get a perfect square?
- 32.Which of these is a perfect square? (a) 1618 (b) 1604 (c) 1600
- 33.What is the smallest whole number by which 96 must be multiplied to get a perfect square?
- 34.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 35.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 36.What is the smallest whole number by which 52 must be multiplied to get a perfect square?
- 37.What is 79²? =
- 38.How many whole numbers lie between 19² and 20²?
- 39.How many whole numbers lie between 41² and 42²?
- 40.A square garden has an area of 2809 square m. How long is each side (in m)?
Answer key
- 900
- 1024
- 30
- 3481
- 81
- 51
- 36
- 21
- 40
- 44
- 34
- 50
- 93
- 47
- 5
- 11
- 60
- 66
- 3
- 784
- 5
- 784
- 10
- 17
- 49
- 13
- 26
- 79
- 13
- 256
- 6
- 1600
- 6
- 256
- 729
- 13
- 6241
- 38
- 82
- 53
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