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 sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 2.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 3.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 4.What is 23²? =
- 5.What is √841? =
- 6.How many whole numbers lie between 46² and 47²?
- 7.What is √1936? =
- 8.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 9.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 10.What is 70²? =
- 11.What is 98²? =
- 12.What is the smallest whole number by which 75 must be multiplied to get a perfect square?
- 13.What is 75²? =
- 14.Which of these is a perfect square? (a) 184 (b) 169 (c) 173
- 15.Which of these is a perfect square? (a) 413 (b) 436 (c) 400
- 16.What is the smallest whole number by which 180 must be multiplied to get a perfect square?
- 17.What is √4761? =
- 18.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 19.A square garden has an area of 1936 square m. How long is each side (in m)?
- 20.How many whole numbers lie between 21² and 22²?
- 21.What is 95²? =
- 22.How many whole numbers lie between 24² and 25²?
- 23.Which of these is a perfect square? (a) 1188 (b) 1171 (c) 1156
- 24.A square garden has an area of 2304 square m. How long is each side (in m)?
- 25.How many whole numbers lie between 13² and 14²?
- 26.What is √1225? =
- 27.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 28.A square garden has an area of 324 square m. How long is each side (in m)?
- 29.What is √2025? =
- 30.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 31.What is 68²? =
- 32.What is 14²? =
- 33.What is the smallest whole number by which 504 must be multiplied to get a perfect square?
- 34.A square garden has an area of 2704 square m. How long is each side (in m)?
- 35.A square garden has an area of 676 square m. How long is each side (in m)?
- 36.What is √1156? =
- 37.Which of these is a perfect square? (a) 588 (b) 576 (c) 600
- 38.What is √361? =
- 39.How many whole numbers lie between 31² and 32²?
- 40.Which of these is a perfect square? (a) 121 (b) 139 (c) 143
Answer key
- 576
- 225
- 100
- 529
- 29
- 92
- 44
- 900
- 625
- 4900
- 9604
- 3
- 5625
- 169
- 400
- 5
- 69
- 676
- 44
- 42
- 9025
- 48
- 1156
- 48
- 26
- 35
- 25
- 18
- 45
- 841
- 4624
- 196
- 14
- 52
- 26
- 34
- 576
- 19
- 62
- 121
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