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 12 odd numbers (1 + 3 + 5 + …)?
- 2.What is the smallest whole number by which 325 must be multiplied to get a perfect square?
- 3.What is the smallest whole number by which 245 must be divided to get a perfect square?
- 4.What is the smallest whole number by which 12 must be divided to get a perfect square?
- 5.What is 46²? =
- 6.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 7.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 8.How many whole numbers lie between 44² and 45²?
- 9.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 10.What is √169? =
- 11.What is 54²? =
- 12.What is √361? =
- 13.What is 64²? =
- 14.How many whole numbers lie between 14² and 15²?
- 15.What is the smallest whole number by which 832 must be multiplied to get a perfect square?
- 16.What is the smallest whole number by which 8 must be multiplied to get a perfect square?
- 17.A square garden has an area of 256 square m. How long is each side (in m)?
- 18.What is √2500? =
- 19.How many whole numbers lie between 45² and 46²?
- 20.Which of these is a perfect square? (a) 1230 (b) 1225 (c) 1277
- 21.How many whole numbers lie between 46² and 47²?
- 22.What is √121? =
- 23.How many whole numbers lie between 36² and 37²?
- 24.A square garden has an area of 1521 square m. How long is each side (in m)?
- 25.A square garden has an area of 100 square m. How long is each side (in m)?
- 26.How many whole numbers lie between 21² and 22²?
- 27.What is 78²? =
- 28.How many whole numbers lie between 12² and 13²?
- 29.What is the smallest whole number by which 60 must be multiplied to get a perfect square?
- 30.How many whole numbers lie between 26² and 27²?
- 31.What is √2209? =
- 32.What is √441? =
- 33.A square garden has an area of 81 square m. How long is each side (in m)?
- 34.A square garden has an area of 1156 square m. How long is each side (in m)?
- 35.Which of these is a perfect square? (a) 491 (b) 484 (c) 493
- 36.What is √1681? =
- 37.How many whole numbers lie between 28² and 29²?
- 38.What is 67²? =
- 39.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 40.A square garden has an area of 1936 square m. How long is each side (in m)?
Answer key
- 144
- 13
- 5
- 3
- 2116
- 625
- 36
- 88
- 900
- 13
- 2916
- 19
- 4096
- 28
- 13
- 2
- 16
- 50
- 90
- 1225
- 92
- 11
- 72
- 39
- 10
- 42
- 6084
- 24
- 15
- 52
- 47
- 21
- 9
- 34
- 484
- 41
- 56
- 4489
- 484
- 44
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