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 smallest whole number by which 128 must be divided to get a perfect square?
- 2.What is √2601? =
- 3.What is 80²? =
- 4.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
- 5.How many whole numbers lie between 46² and 47²?
- 6.What is √1369? =
- 7.A square garden has an area of 400 square m. How long is each side (in m)?
- 8.A square garden has an area of 961 square m. How long is each side (in m)?
- 9.What is the smallest whole number by which 160 must be divided to get a perfect square?
- 10.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 11.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 12.What is 35²? =
- 13.A square garden has an area of 1369 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 196 (b) 219 (c) 197
- 15.Which of these is a perfect square? (a) 806 (b) 784 (c) 810
- 16.What is 39²? =
- 17.How many whole numbers lie between 16² and 17²?
- 18.What is √6724? =
- 19.Which of these is a perfect square? (a) 100 (b) 108 (c) 109
- 20.What is √529? =
- 21.What is 53²? =
- 22.Which of these is a perfect square? (a) 141 (b) 129 (c) 121
- 23.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 24.What is √3721? =
- 25.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 26.A square garden has an area of 64 square m. How long is each side (in m)?
- 27.What is √2025? =
- 28.What is the smallest whole number by which 162 must be divided to get a perfect square?
- 29.Which of these is a perfect square? (a) 430 (b) 400 (c) 402
- 30.What is 33²? =
- 31.What is √6889? =
- 32.What is the smallest whole number by which 80 must be divided to get a perfect square?
- 33.What is √144? =
- 34.How many whole numbers lie between 9² and 10²?
- 35.Which of these is a perfect square? (a) 739 (b) 760 (c) 729
- 36.How many whole numbers lie between 12² and 13²?
- 37.What is √7921? =
- 38.What is the smallest whole number by which 896 must be divided to get a perfect square?
- 39.What is √9604? =
- 40.What is √784? =
Answer key
- 2
- 51
- 6400
- 2
- 92
- 37
- 20
- 31
- 10
- 196
- 484
- 1225
- 37
- 196
- 784
- 1521
- 32
- 82
- 100
- 23
- 2809
- 121
- 625
- 61
- 144
- 8
- 45
- 2
- 400
- 1089
- 83
- 5
- 12
- 18
- 729
- 24
- 89
- 14
- 98
- 28
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