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 25 odd numbers (1 + 3 + 5 + …)?
- 2.What is 99²? =
- 3.How many whole numbers lie between 6² and 7²?
- 4.What is 29²? =
- 5.How many whole numbers lie between 29² and 30²?
- 6.What is √7744? =
- 7.What is the smallest whole number by which 60 must be multiplied to get a perfect square?
- 8.What is √2304? =
- 9.Which of these is a perfect square? (a) 355 (b) 324 (c) 343
- 10.Which of these is a perfect square? (a) 729 (b) 759 (c) 752
- 11.What is √529? =
- 12.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 13.How many whole numbers lie between 49² and 50²?
- 14.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 15.What is 67²? =
- 16.Which of these is a perfect square? (a) 1169 (b) 1156 (c) 1176
- 17.What is the smallest whole number by which 54 must be divided to get a perfect square?
- 18.Which of these is a perfect square? (a) 961 (b) 1016 (c) 962
- 19.What is √1681? =
- 20.What is the smallest whole number by which 960 must be multiplied to get a perfect square?
- 21.Which of these is a perfect square? (a) 144 (b) 168 (c) 157
- 22.What is the smallest whole number by which 540 must be multiplied to get a perfect square?
- 23.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 24.How many whole numbers lie between 15² and 16²?
- 25.What is √784? =
- 26.A square garden has an area of 144 square m. How long is each side (in m)?
- 27.What is 22²? =
- 28.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 29.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 30.What is the smallest whole number by which 240 must be divided to get a perfect square?
- 31.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 32.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 33.A square garden has an area of 3364 square m. How long is each side (in m)?
- 34.How many whole numbers lie between 17² and 18²?
- 35.What is 92²? =
- 36.What is 71²? =
- 37.What is the smallest whole number by which 135 must be divided to get a perfect square?
- 38.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 39.A square garden has an area of 1444 square m. How long is each side (in m)?
- 40.What is the smallest whole number by which 896 must be divided to get a perfect square?
Answer key
- 625
- 9801
- 12
- 841
- 58
- 88
- 15
- 48
- 324
- 729
- 23
- 121
- 98
- 36
- 4489
- 1156
- 6
- 961
- 41
- 15
- 144
- 15
- 784
- 30
- 28
- 12
- 484
- 25
- 225
- 15
- 400
- 484
- 58
- 34
- 8464
- 5041
- 15
- 196
- 38
- 14
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