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.A square garden has an area of 1225 square m. How long is each side (in m)?
- 2.Which of these is a perfect square? (a) 261 (b) 256 (c) 264
- 3.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 4.How many whole numbers lie between 41² and 42²?
- 5.What is the smallest whole number by which 216 must be divided to get a perfect square?
- 6.How many whole numbers lie between 12² and 13²?
- 7.What is 21²? =
- 8.A square garden has an area of 2500 square m. How long is each side (in m)?
- 9.What is the smallest whole number by which 832 must be divided to get a perfect square?
- 10.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 11.What is √4900? =
- 12.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 13.A square garden has an area of 25 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 1233 (b) 1225 (c) 1253
- 15.A square garden has an area of 1444 square m. How long is each side (in m)?
- 16.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 17.What is 51²? =
- 18.What is the smallest whole number by which 32 must be divided to get a perfect square?
- 19.What is 39²? =
- 20.What is the smallest whole number by which 175 must be divided to get a perfect square?
- 21.A square garden has an area of 1681 square m. How long is each side (in m)?
- 22.How many whole numbers lie between 32² and 33²?
- 23.What is √529? =
- 24.What is 41²? =
- 25.What is 22²? =
- 26.How many whole numbers lie between 26² and 27²?
- 27.What is 42²? =
- 28.What is √2304? =
- 29.A square garden has an area of 36 square m. How long is each side (in m)?
- 30.A square garden has an area of 196 square m. How long is each side (in m)?
- 31.What is the smallest whole number by which 96 must be multiplied to get a perfect square?
- 32.What is √9216? =
- 33.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 34.What is 87²? =
- 35.How many whole numbers lie between 15² and 16²?
- 36.What is the smallest whole number by which 245 must be multiplied to get a perfect square?
- 37.What is √7396? =
- 38.What is the smallest whole number by which 243 must be divided to get a perfect square?
- 39.What is 40²? =
- 40.What is the smallest whole number by which 63 must be divided to get a perfect square?
Answer key
- 35
- 256
- 36
- 82
- 6
- 24
- 441
- 50
- 13
- 81
- 70
- 529
- 5
- 1225
- 38
- 900
- 2601
- 2
- 1521
- 7
- 41
- 64
- 23
- 1681
- 484
- 52
- 1764
- 48
- 6
- 14
- 6
- 96
- 361
- 7569
- 30
- 5
- 86
- 3
- 1600
- 7
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