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 6 odd numbers (1 + 3 + 5 + …)?
- 2.A square garden has an area of 225 square m. How long is each side (in m)?
- 3.How many whole numbers lie between 18² and 19²?
- 4.What is the smallest whole number by which 96 must be divided to get a perfect square?
- 5.What is 15²? =
- 6.How many whole numbers lie between 13² and 14²?
- 7.Which of these is a perfect square? (a) 872 (b) 843 (c) 841
- 8.Which of these is a perfect square? (a) 794 (b) 784 (c) 814
- 9.What is the smallest whole number by which 243 must be multiplied to get a perfect square?
- 10.How many whole numbers lie between 30² and 31²?
- 11.A square garden has an area of 2304 square m. How long is each side (in m)?
- 12.What is 25²? =
- 13.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 14.What is the smallest whole number by which 504 must be divided to get a perfect square?
- 15.Which of these is a perfect square? (a) 256 (b) 259 (c) 267
- 16.What is √784? =
- 17.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 18.What is √2500? =
- 19.What is √2116? =
- 20.What is √1296? =
- 21.What is √1225? =
- 22.A square garden has an area of 2601 square m. How long is each side (in m)?
- 23.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 24.What is the smallest whole number by which 567 must be multiplied to get a perfect square?
- 25.Which of these is a perfect square? (a) 627 (b) 625 (c) 662
- 26.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 27.What is √484? =
- 28.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 29.A square garden has an area of 900 square m. How long is each side (in m)?
- 30.How many whole numbers lie between 35² and 36²?
- 31.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 32.What is the smallest whole number by which 396 must be multiplied to get a perfect square?
- 33.How many whole numbers lie between 10² and 11²?
- 34.What is 28²? =
- 35.What is √3136? =
- 36.A square garden has an area of 1156 square m. How long is each side (in m)?
- 37.Which of these is a perfect square? (a) 1397 (b) 1369 (c) 1385
- 38.What is 42²? =
- 39.What is 21²? =
- 40.What is the smallest whole number by which 75 must be multiplied to get a perfect square?
Answer key
- 36
- 15
- 36
- 6
- 225
- 26
- 841
- 784
- 3
- 60
- 48
- 625
- 144
- 14
- 256
- 28
- 289
- 50
- 46
- 36
- 35
- 51
- 196
- 7
- 625
- 729
- 22
- 484
- 30
- 70
- 100
- 11
- 20
- 784
- 56
- 34
- 1369
- 1764
- 441
- 3
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