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 √4900? =
- 2.Which of these is a perfect square? (a) 275 (b) 256 (c) 281
- 3.Which of these is a perfect square? (a) 795 (b) 784 (c) 816
- 4.How many whole numbers lie between 41² and 42²?
- 5.What is √784? =
- 6.What is 29²? =
- 7.What is 50²? =
- 8.What is 19²? =
- 9.Which of these is a perfect square? (a) 138 (b) 121 (c) 141
- 10.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 11.A square garden has an area of 400 square m. How long is each side (in m)?
- 12.Which of these is a perfect square? (a) 1444 (b) 1469 (c) 1450
- 13.What is 25²? =
- 14.What is √1521? =
- 15.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 16.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 17.A square garden has an area of 1764 square m. How long is each side (in m)?
- 18.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 19.What is 69²? =
- 20.What is 23²? =
- 21.A square garden has an area of 289 square m. How long is each side (in m)?
- 22.What is √361? =
- 23.What is √6241? =
- 24.What is the smallest whole number by which 117 must be multiplied to get a perfect square?
- 25.What is √196? =
- 26.What is √4761? =
- 27.What is √5625? =
- 28.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 29.What is 68²? =
- 30.Which of these is a perfect square? (a) 406 (b) 429 (c) 400
- 31.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 32.Which of these is a perfect square? (a) 1232 (b) 1225 (c) 1244
- 33.A square garden has an area of 25 square m. How long is each side (in m)?
- 34.What is √1024? =
- 35.What is the smallest whole number by which 24 must be divided to get a perfect square?
- 36.A square garden has an area of 169 square m. How long is each side (in m)?
- 37.What is the smallest whole number by which 252 must be divided to get a perfect square?
- 38.What is the smallest whole number by which 32 must be multiplied to get a perfect square?
- 39.A square garden has an area of 961 square m. How long is each side (in m)?
- 40.How many whole numbers lie between 46² and 47²?
Answer key
- 70
- 256
- 784
- 82
- 28
- 841
- 2500
- 361
- 121
- 529
- 20
- 1444
- 625
- 39
- 3
- 81
- 42
- 289
- 4761
- 529
- 17
- 19
- 79
- 13
- 14
- 69
- 75
- 841
- 4624
- 400
- 441
- 1225
- 5
- 32
- 6
- 13
- 7
- 2
- 31
- 92
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