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 126 must be divided to get a perfect square?
- 2.A square garden has an area of 529 square m. How long is each side (in m)?
- 3.What is 64²? =
- 4.Which of these is a perfect square? (a) 1527 (b) 1521 (c) 1543
- 5.What is 20²? =
- 6.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 7.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 8.What is 91²? =
- 9.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 10.Which of these is a perfect square? (a) 202 (b) 196 (c) 216
- 11.What is 93²? =
- 12.A square garden has an area of 3025 square m. How long is each side (in m)?
- 13.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
- 14.What is √5476? =
- 15.What is 25²? =
- 16.What is 31²? =
- 17.What is 26²? =
- 18.What is √7569? =
- 19.Which of these is a perfect square? (a) 225 (b) 239 (c) 242
- 20.What is √5184? =
- 21.Which of these is a perfect square? (a) 1509 (b) 1503 (c) 1444
- 22.How many whole numbers lie between 17² and 18²?
- 23.What is √196? =
- 24.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 25.What is the smallest whole number by which 56 must be multiplied to get a perfect square?
- 26.What is √4761? =
- 27.What is 41²? =
- 28.What is √900? =
- 29.A square garden has an area of 3600 square m. How long is each side (in m)?
- 30.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 31.What is √3600? =
- 32.What is the smallest whole number by which 832 must be multiplied to get a perfect square?
- 33.What is √4624? =
- 34.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 35.What is the smallest whole number by which 224 must be multiplied to get a perfect square?
- 36.Which of these is a perfect square? (a) 102 (b) 116 (c) 100
- 37.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 38.What is √576? =
- 39.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 40.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
Answer key
- 14
- 23
- 4096
- 1521
- 400
- 36
- 289
- 8281
- 121
- 196
- 8649
- 55
- 15
- 74
- 625
- 961
- 676
- 87
- 225
- 72
- 1444
- 34
- 14
- 196
- 14
- 69
- 1681
- 30
- 60
- 529
- 60
- 13
- 68
- 400
- 14
- 100
- 3
- 24
- 169
- 144
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