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 80 must be multiplied to get a perfect square?
- 2.What is 95²? =
- 3.What is 28²? =
- 4.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 5.How many whole numbers lie between 39² and 40²?
- 6.How many whole numbers lie between 47² and 48²?
- 7.Which of these is a perfect square? (a) 686 (b) 676 (c) 684
- 8.What is √7921? =
- 9.Which of these is a perfect square? (a) 528 (b) 484 (c) 505
- 10.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
- 11.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 12.What is √6889? =
- 13.How many whole numbers lie between 6² and 7²?
- 14.Which of these is a perfect square? (a) 1510 (b) 1474 (c) 1444
- 15.Which of these is a perfect square? (a) 1521 (b) 1595 (c) 1588
- 16.How many whole numbers lie between 34² and 35²?
- 17.What is √1849? =
- 18.How many whole numbers lie between 38² and 39²?
- 19.What is √6724? =
- 20.How many whole numbers lie between 11² and 12²?
- 21.How many whole numbers lie between 35² and 36²?
- 22.How many whole numbers lie between 13² and 14²?
- 23.What is 88²? =
- 24.A square garden has an area of 961 square m. How long is each side (in m)?
- 25.What is √7744? =
- 26.What is 66²? =
- 27.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 28.Which of these is a perfect square? (a) 1261 (b) 1259 (c) 1225
- 29.A square garden has an area of 1225 square m. How long is each side (in m)?
- 30.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 31.What is √441? =
- 32.What is 43²? =
- 33.What is 37²? =
- 34.What is 69²? =
- 35.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 36.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 37.What is 12²? =
- 38.What is the smallest whole number by which 96 must be multiplied to get a perfect square?
- 39.Which of these is a perfect square? (a) 333 (b) 324 (c) 336
- 40.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
Answer key
- 5
- 9025
- 784
- 324
- 78
- 94
- 676
- 89
- 484
- 7
- 5
- 83
- 12
- 1444
- 1521
- 68
- 43
- 76
- 82
- 22
- 70
- 26
- 7744
- 31
- 88
- 4356
- 900
- 1225
- 35
- 576
- 21
- 1849
- 1369
- 4761
- 225
- 676
- 144
- 6
- 324
- 144
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