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 35²? =
- 2.What is √576? =
- 3.What is 89²? =
- 4.A square garden has an area of 361 square m. How long is each side (in m)?
- 5.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 6.How many whole numbers lie between 32² and 33²?
- 7.What is the smallest whole number by which 117 must be multiplied to get a perfect square?
- 8.What is 77²? =
- 9.What is 25²? =
- 10.What is √5329? =
- 11.What is the smallest whole number by which 448 must be multiplied to get a perfect square?
- 12.What is 76²? =
- 13.What is √256? =
- 14.Which of these is a perfect square? (a) 183 (b) 169 (c) 184
- 15.What is 67²? =
- 16.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 17.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 18.Which of these is a perfect square? (a) 344 (b) 333 (c) 324
- 19.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 20.What is √1444? =
- 21.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 22.Which of these is a perfect square? (a) 563 (b) 529 (c) 533
- 23.What is √2401? =
- 24.What is the smallest whole number by which 28 must be multiplied to get a perfect square?
- 25.A square garden has an area of 25 square m. How long is each side (in m)?
- 26.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 27.A square garden has an area of 324 square m. How long is each side (in m)?
- 28.How many whole numbers lie between 8² and 9²?
- 29.How many whole numbers lie between 9² and 10²?
- 30.What is 18²? =
- 31.What is 81²? =
- 32.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 33.What is √2500? =
- 34.Which of these is a perfect square? (a) 584 (b) 580 (c) 576
- 35.How many whole numbers lie between 46² and 47²?
- 36.What is the smallest whole number by which 60 must be multiplied to get a perfect square?
- 37.Which of these is a perfect square? (a) 1672 (b) 1679 (c) 1600
- 38.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 39.What is the smallest whole number by which 108 must be divided to get a perfect square?
- 40.What is the smallest whole number by which 1215 must be multiplied to get a perfect square?
Answer key
- 1225
- 24
- 7921
- 19
- 5
- 64
- 13
- 5929
- 625
- 73
- 7
- 5776
- 16
- 169
- 4489
- 49
- 676
- 324
- 225
- 38
- 400
- 529
- 49
- 7
- 5
- 324
- 18
- 16
- 18
- 324
- 6561
- 841
- 50
- 576
- 92
- 15
- 1600
- 361
- 3
- 15
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