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 50 must be multiplied to get a perfect square?
- 2.What is √1089? =
- 3.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 4.How many whole numbers lie between 28² and 29²?
- 5.What is 78²? =
- 6.What is 91²? =
- 7.What is √6561? =
- 8.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 9.What is 94²? =
- 10.What is the smallest whole number by which 45 must be divided to get a perfect square?
- 11.How many whole numbers lie between 20² and 21²?
- 12.A square garden has an area of 3600 square m. How long is each side (in m)?
- 13.How many whole numbers lie between 37² and 38²?
- 14.How many whole numbers lie between 35² and 36²?
- 15.How many whole numbers lie between 12² and 13²?
- 16.What is the smallest whole number by which 384 must be divided to get a perfect square?
- 17.What is 52²? =
- 18.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
- 19.What is √256? =
- 20.Which of these is a perfect square? (a) 282 (b) 256 (c) 273
- 21.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 22.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 23.What is √729? =
- 24.A square garden has an area of 400 square m. How long is each side (in m)?
- 25.How many whole numbers lie between 13² and 14²?
- 26.What is 18²? =
- 27.What is 72²? =
- 28.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
- 29.What is 75²? =
- 30.A square garden has an area of 1521 square m. How long is each side (in m)?
- 31.What is 88²? =
- 32.What is 25²? =
- 33.What is √3136? =
- 34.What is 30²? =
- 35.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 36.What is √676? =
- 37.What is 22²? =
- 38.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 39.A square garden has an area of 841 square m. How long is each side (in m)?
- 40.What is √4489? =
Answer key
- 2
- 33
- 676
- 56
- 6084
- 8281
- 81
- 900
- 8836
- 5
- 40
- 60
- 74
- 70
- 24
- 6
- 2704
- 7
- 16
- 256
- 196
- 625
- 27
- 20
- 26
- 324
- 5184
- 15
- 5625
- 39
- 7744
- 625
- 56
- 900
- 144
- 26
- 484
- 169
- 29
- 67
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