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 √3249? =
- 2.What is 49²? =
- 3.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 4.Which of these is a perfect square? (a) 241 (b) 225 (c) 248
- 5.What is 83²? =
- 6.How many whole numbers lie between 48² and 49²?
- 7.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 8.What is 30²? =
- 9.How many whole numbers lie between 9² and 10²?
- 10.How many whole numbers lie between 7² and 8²?
- 11.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 12.What is the smallest whole number by which 360 must be multiplied to get a perfect square?
- 13.What is √400? =
- 14.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 15.How many whole numbers lie between 39² and 40²?
- 16.A square garden has an area of 64 square m. How long is each side (in m)?
- 17.What is 54²? =
- 18.What is √2025? =
- 19.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 20.What is √1849? =
- 21.What is 55²? =
- 22.A square garden has an area of 1764 square m. How long is each side (in m)?
- 23.What is √4624? =
- 24.What is √1089? =
- 25.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 26.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 27.What is √576? =
- 28.What is 69²? =
- 29.What is 23²? =
- 30.Which of these is a perfect square? (a) 186 (b) 179 (c) 169
- 31.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 32.A square garden has an area of 1444 square m. How long is each side (in m)?
- 33.What is 80²? =
- 34.A square garden has an area of 256 square m. How long is each side (in m)?
- 35.How many whole numbers lie between 6² and 7²?
- 36.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 37.How many whole numbers lie between 47² and 48²?
- 38.What is the smallest whole number by which 240 must be multiplied to get a perfect square?
- 39.What is √324? =
- 40.What is the smallest whole number by which 486 must be multiplied to get a perfect square?
Answer key
- 57
- 2401
- 169
- 225
- 6889
- 96
- 100
- 900
- 18
- 14
- 400
- 10
- 20
- 361
- 78
- 8
- 2916
- 45
- 784
- 43
- 3025
- 42
- 68
- 33
- 196
- 900
- 24
- 4761
- 529
- 169
- 841
- 38
- 6400
- 16
- 12
- 225
- 94
- 15
- 18
- 6
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