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 √5041? =
- 2.Which of these is a perfect square? (a) 257 (b) 256 (c) 263
- 3.How many whole numbers lie between 39² and 40²?
- 4.What is 29²? =
- 5.What is 30²? =
- 6.Which of these is a perfect square? (a) 125 (b) 121 (c) 124
- 7.A square garden has an area of 2601 square m. How long is each side (in m)?
- 8.Which of these is a perfect square? (a) 665 (b) 625 (c) 643
- 9.What is √441? =
- 10.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 11.What is √1444? =
- 12.What is the smallest whole number by which 1134 must be divided to get a perfect square?
- 13.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 14.How many whole numbers lie between 20² and 21²?
- 15.What is √2209? =
- 16.What is 69²? =
- 17.What is 15²? =
- 18.How many whole numbers lie between 17² and 18²?
- 19.What is the smallest whole number by which 250 must be divided to get a perfect square?
- 20.What is √2601? =
- 21.What is 93²? =
- 22.What is the smallest whole number by which 486 must be multiplied to get a perfect square?
- 23.What is √169? =
- 24.What is √6241? =
- 25.What is √7225? =
- 26.What is the smallest whole number by which 75 must be divided to get a perfect square?
- 27.What is √1296? =
- 28.What is the smallest whole number by which 1134 must be multiplied to get a perfect square?
- 29.A square garden has an area of 3600 square m. How long is each side (in m)?
- 30.A square garden has an area of 225 square m. How long is each side (in m)?
- 31.How many whole numbers lie between 13² and 14²?
- 32.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 33.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
- 34.How many whole numbers lie between 18² and 19²?
- 35.Which of these is a perfect square? (a) 927 (b) 949 (c) 900
- 36.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 37.What is 59²? =
- 38.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 39.What is √6561? =
- 40.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
Answer key
- 71
- 256
- 78
- 841
- 900
- 121
- 51
- 625
- 21
- 784
- 38
- 14
- 25
- 40
- 47
- 4761
- 225
- 34
- 10
- 51
- 8649
- 6
- 13
- 79
- 85
- 3
- 36
- 14
- 60
- 15
- 26
- 324
- 2
- 36
- 900
- 441
- 3481
- 625
- 81
- 121
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