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 29 odd numbers (1 + 3 + 5 + …)?
- 2.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 3.What is 87²? =
- 4.What is √289? =
- 5.How many whole numbers lie between 31² and 32²?
- 6.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
- 7.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 8.What is the smallest whole number by which 448 must be multiplied to get a perfect square?
- 9.How many whole numbers lie between 17² and 18²?
- 10.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 11.What is 17²? =
- 12.A square garden has an area of 2116 square m. How long is each side (in m)?
- 13.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 14.What is √9604? =
- 15.A square garden has an area of 3481 square m. How long is each side (in m)?
- 16.What is 58²? =
- 17.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 18.What is the smallest whole number by which 20 must be multiplied to get a perfect square?
- 19.What is the smallest whole number by which 112 must be divided to get a perfect square?
- 20.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 21.What is √3600? =
- 22.Which of these is a perfect square? (a) 256 (b) 259 (c) 272
- 23.What is √4096? =
- 24.Which of these is a perfect square? (a) 196 (b) 216 (c) 211
- 25.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 26.What is 52²? =
- 27.What is 14²? =
- 28.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 29.How many whole numbers lie between 9² and 10²?
- 30.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 31.What is √6561? =
- 32.What is 36²? =
- 33.What is 45²? =
- 34.A square garden has an area of 2809 square m. How long is each side (in m)?
- 35.What is √1521? =
- 36.Which of these is a perfect square? (a) 1376 (b) 1398 (c) 1369
- 37.What is 38²? =
- 38.Which of these is a perfect square? (a) 900 (b) 905 (c) 947
- 39.What is √5329? =
- 40.What is 63²? =
Answer key
- 841
- 121
- 7569
- 17
- 62
- 2
- 529
- 7
- 34
- 676
- 289
- 46
- 196
- 98
- 59
- 3364
- 5
- 5
- 7
- 576
- 60
- 256
- 64
- 196
- 361
- 2704
- 196
- 289
- 18
- 100
- 81
- 1296
- 2025
- 53
- 39
- 1369
- 1444
- 900
- 73
- 3969
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