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.How many whole numbers lie between 5² and 6²?
- 2.How many whole numbers lie between 14² and 15²?
- 3.What is √9604? =
- 4.How many whole numbers lie between 31² and 32²?
- 5.What is 36²? =
- 6.What is the smallest whole number by which 72 must be multiplied to get a perfect square?
- 7.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 8.What is √1936? =
- 9.What is the smallest whole number by which 60 must be multiplied to get a perfect square?
- 10.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 11.What is √2601? =
- 12.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 13.What is √6400? =
- 14.What is the smallest whole number by which 50 must be divided to get a perfect square?
- 15.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 16.What is √1849? =
- 17.What is 20²? =
- 18.Which of these is a perfect square? (a) 107 (b) 100 (c) 103
- 19.What is 45²? =
- 20.A square garden has an area of 1936 square m. How long is each side (in m)?
- 21.Which of these is a perfect square? (a) 1329 (b) 1296 (c) 1324
- 22.What is the smallest whole number by which 468 must be divided to get a perfect square?
- 23.What is √784? =
- 24.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 25.What is √4761? =
- 26.What is √625? =
- 27.What is the smallest whole number by which 28 must be multiplied to get a perfect square?
- 28.What is 13²? =
- 29.Which of these is a perfect square? (a) 1565 (b) 1521 (c) 1562
- 30.A square garden has an area of 144 square m. How long is each side (in m)?
- 31.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 32.Which of these is a perfect square? (a) 1172 (b) 1161 (c) 1156
- 33.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 34.What is √2916? =
- 35.How many whole numbers lie between 44² and 45²?
- 36.A square garden has an area of 361 square m. How long is each side (in m)?
- 37.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 38.What is √6241? =
- 39.What is the smallest whole number by which 108 must be divided to get a perfect square?
- 40.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
Answer key
- 10
- 28
- 98
- 62
- 1296
- 2
- 400
- 44
- 15
- 256
- 51
- 676
- 80
- 2
- 841
- 43
- 400
- 100
- 2025
- 44
- 1296
- 13
- 28
- 625
- 69
- 25
- 7
- 169
- 1521
- 12
- 49
- 1156
- 169
- 54
- 88
- 19
- 144
- 79
- 3
- 7
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