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.Which of these is a perfect square? (a) 245 (b) 225 (c) 228
- 2.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 3.What is 31²? =
- 4.What is √8836? =
- 5.What is 84²? =
- 6.What is the smallest whole number by which 224 must be multiplied to get a perfect square?
- 7.What is the smallest whole number by which 63 must be multiplied to get a perfect square?
- 8.A square garden has an area of 1369 square m. How long is each side (in m)?
- 9.What is 70²? =
- 10.What is √961? =
- 11.What is √2916? =
- 12.What is √5184? =
- 13.A square garden has an area of 400 square m. How long is each side (in m)?
- 14.What is 83²? =
- 15.What is 26²? =
- 16.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 17.What is the smallest whole number by which 44 must be divided to get a perfect square?
- 18.What is √5776? =
- 19.What is 44²? =
- 20.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 21.Which of these is a perfect square? (a) 410 (b) 421 (c) 400
- 22.What is 72²? =
- 23.What is 36²? =
- 24.What is the smallest whole number by which 486 must be divided to get a perfect square?
- 25.A square garden has an area of 900 square m. How long is each side (in m)?
- 26.What is 94²? =
- 27.What is the smallest whole number by which 1134 must be multiplied to get a perfect square?
- 28.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 29.What is the smallest whole number by which 735 must be divided to get a perfect square?
- 30.What is 16²? =
- 31.What is √9801? =
- 32.What is the smallest whole number by which 52 must be divided to get a perfect square?
- 33.How many whole numbers lie between 20² and 21²?
- 34.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 35.What is √7396? =
- 36.A square garden has an area of 169 square m. How long is each side (in m)?
- 37.Which of these is a perfect square? (a) 364 (b) 386 (c) 361
- 38.How many whole numbers lie between 21² and 22²?
- 39.What is √8281? =
- 40.What is √3025? =
Answer key
- 225
- 25
- 961
- 94
- 7056
- 14
- 7
- 37
- 4900
- 31
- 54
- 72
- 20
- 6889
- 676
- 169
- 11
- 76
- 1936
- 49
- 400
- 5184
- 1296
- 6
- 30
- 8836
- 14
- 64
- 15
- 256
- 99
- 13
- 40
- 529
- 86
- 13
- 361
- 42
- 91
- 55
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