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 53²? =
- 2.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 3.What is the smallest whole number by which 117 must be divided to get a perfect square?
- 4.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 5.What is 18²? =
- 6.What is the smallest whole number by which 40 must be divided to get a perfect square?
- 7.What is 67²? =
- 8.What is 46²? =
- 9.What is the smallest whole number by which 539 must be divided to get a perfect square?
- 10.What is 45²? =
- 11.Which of these is a perfect square? (a) 1369 (b) 1403 (c) 1436
- 12.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
- 13.A square garden has an area of 144 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 225 (b) 249 (c) 243
- 15.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 16.What is 30²? =
- 17.What is 89²? =
- 18.What is √9216? =
- 19.What is 14²? =
- 20.Which of these is a perfect square? (a) 148 (b) 164 (c) 144
- 21.Which of these is a perfect square? (a) 961 (b) 1019 (c) 1014
- 22.What is √121? =
- 23.What is the smallest whole number by which 112 must be divided to get a perfect square?
- 24.A square garden has an area of 1849 square m. How long is each side (in m)?
- 25.Which of these is a perfect square? (a) 175 (b) 185 (c) 169
- 26.What is √2025? =
- 27.What is √1225? =
- 28.How many whole numbers lie between 30² and 31²?
- 29.What is 68²? =
- 30.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 31.What is √4356? =
- 32.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
- 33.How many whole numbers lie between 44² and 45²?
- 34.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
- 35.What is the smallest whole number by which 147 must be divided to get a perfect square?
- 36.What is √4900? =
- 37.What is 13²? =
- 38.How many whole numbers lie between 18² and 19²?
- 39.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 40.Which of these is a perfect square? (a) 587 (b) 588 (c) 576
Answer key
- 2809
- 784
- 13
- 400
- 324
- 10
- 4489
- 2116
- 11
- 2025
- 1369
- 15
- 12
- 225
- 49
- 900
- 7921
- 96
- 196
- 144
- 961
- 11
- 7
- 43
- 169
- 45
- 35
- 60
- 4624
- 529
- 66
- 2
- 88
- 3
- 3
- 70
- 169
- 36
- 25
- 576
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