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 23 odd numbers (1 + 3 + 5 + …)?
- 2.A square garden has an area of 81 square m. How long is each side (in m)?
- 3.What is 46²? =
- 4.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 5.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 6.How many whole numbers lie between 35² and 36²?
- 7.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 8.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 9.What is 16²? =
- 10.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 11.What is 80²? =
- 12.What is 31²? =
- 13.What is √7569? =
- 14.What is √169? =
- 15.How many whole numbers lie between 37² and 38²?
- 16.What is the smallest whole number by which 27 must be divided to get a perfect square?
- 17.What is the smallest whole number by which 896 must be divided to get a perfect square?
- 18.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 19.What is √144? =
- 20.What is √4900? =
- 21.A square garden has an area of 1296 square m. How long is each side (in m)?
- 22.A square garden has an area of 289 square m. How long is each side (in m)?
- 23.How many whole numbers lie between 27² and 28²?
- 24.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 25.What is √2704? =
- 26.How many whole numbers lie between 36² and 37²?
- 27.What is the smallest whole number by which 486 must be multiplied to get a perfect square?
- 28.A square garden has an area of 1089 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 343 must be divided to get a perfect square?
- 30.What is √7921? =
- 31.Which of these is a perfect square? (a) 121 (b) 137 (c) 131
- 32.What is 53²? =
- 33.What is 67²? =
- 34.A square garden has an area of 3249 square m. How long is each side (in m)?
- 35.How many whole numbers lie between 18² and 19²?
- 36.What is √6561? =
- 37.A square garden has an area of 1369 square m. How long is each side (in m)?
- 38.A square garden has an area of 256 square m. How long is each side (in m)?
- 39.What is the smallest whole number by which 1053 must be divided to get a perfect square?
- 40.What is √9604? =
Answer key
- 529
- 9
- 2116
- 841
- 784
- 70
- 3
- 400
- 256
- 900
- 6400
- 961
- 87
- 13
- 74
- 3
- 14
- 625
- 12
- 70
- 36
- 17
- 54
- 169
- 52
- 72
- 6
- 33
- 7
- 89
- 121
- 2809
- 4489
- 57
- 36
- 81
- 37
- 16
- 13
- 98
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