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 √841? =
- 2.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 3.How many whole numbers lie between 34² and 35²?
- 4.How many whole numbers lie between 31² and 32²?
- 5.Which of these is a perfect square? (a) 324 (b) 350 (c) 360
- 6.What is √1521? =
- 7.What is 62²? =
- 8.What is the smallest whole number by which 128 must be multiplied to get a perfect square?
- 9.How many whole numbers lie between 48² and 49²?
- 10.How many whole numbers lie between 28² and 29²?
- 11.A square garden has an area of 1296 square m. How long is each side (in m)?
- 12.Which of these is a perfect square? (a) 295 (b) 289 (c) 293
- 13.A square garden has an area of 3600 square m. How long is each side (in m)?
- 14.A square garden has an area of 144 square m. How long is each side (in m)?
- 15.What is the smallest whole number by which 1134 must be multiplied to get a perfect square?
- 16.What is √8649? =
- 17.How many whole numbers lie between 39² and 40²?
- 18.What is √6724? =
- 19.What is the smallest whole number by which 150 must be multiplied to get a perfect square?
- 20.A square garden has an area of 1024 square m. How long is each side (in m)?
- 21.How many whole numbers lie between 35² and 36²?
- 22.What is 75²? =
- 23.A square garden has an area of 49 square m. How long is each side (in m)?
- 24.What is √1444? =
- 25.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 26.What is 64²? =
- 27.How many whole numbers lie between 29² and 30²?
- 28.A square garden has an area of 121 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 18² and 19²?
- 30.What is √4900? =
- 31.A square garden has an area of 400 square m. How long is each side (in m)?
- 32.What is √9025? =
- 33.What is √1369? =
- 34.A square garden has an area of 36 square m. How long is each side (in m)?
- 35.What is 74²? =
- 36.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 37.What is 15²? =
- 38.What is √7225? =
- 39.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 40.How many whole numbers lie between 16² and 17²?
Answer key
- 29
- 196
- 68
- 62
- 324
- 39
- 3844
- 2
- 96
- 56
- 36
- 289
- 60
- 12
- 14
- 93
- 78
- 82
- 6
- 32
- 70
- 5625
- 7
- 38
- 324
- 4096
- 58
- 11
- 36
- 70
- 20
- 95
- 37
- 6
- 5476
- 225
- 225
- 85
- 484
- 32
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