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 20² and 21²?
- 2.How many whole numbers lie between 18² and 19²?
- 3.A square garden has an area of 1681 square m. How long is each side (in m)?
- 4.What is 78²? =
- 5.How many whole numbers lie between 17² and 18²?
- 6.A square garden has an area of 1369 square m. How long is each side (in m)?
- 7.What is 23²? =
- 8.How many whole numbers lie between 44² and 45²?
- 9.What is 68²? =
- 10.How many whole numbers lie between 8² and 9²?
- 11.What is 76²? =
- 12.How many whole numbers lie between 25² and 26²?
- 13.What is 48²? =
- 14.What is 96²? =
- 15.How many whole numbers lie between 11² and 12²?
- 16.Which of these is a perfect square? (a) 144 (b) 148 (c) 164
- 17.What is the smallest whole number by which 192 must be divided to get a perfect square?
- 18.Which of these is a perfect square? (a) 228 (b) 245 (c) 225
- 19.What is √5929? =
- 20.How many whole numbers lie between 34² and 35²?
- 21.What is 88²? =
- 22.What is √4900? =
- 23.What is 33²? =
- 24.Which of these is a perfect square? (a) 289 (b) 293 (c) 319
- 25.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 26.Which of these is a perfect square? (a) 1156 (b) 1162 (c) 1180
- 27.What is 83²? =
- 28.What is √4096? =
- 29.How many whole numbers lie between 7² and 8²?
- 30.What is √729? =
- 31.What is 90²? =
- 32.What is the smallest whole number by which 117 must be multiplied to get a perfect square?
- 33.Which of these is a perfect square? (a) 263 (b) 256 (c) 286
- 34.How many whole numbers lie between 9² and 10²?
- 35.A square garden has an area of 3481 square m. How long is each side (in m)?
- 36.What is √9604? =
- 37.Which of these is a perfect square? (a) 1467 (b) 1460 (c) 1444
- 38.How many whole numbers lie between 27² and 28²?
- 39.A square garden has an area of 3249 square m. How long is each side (in m)?
- 40.What is 86²? =
Answer key
- 40
- 36
- 41
- 6084
- 34
- 37
- 529
- 88
- 4624
- 16
- 5776
- 50
- 2304
- 9216
- 22
- 144
- 3
- 225
- 77
- 68
- 7744
- 70
- 1089
- 289
- 49
- 1156
- 6889
- 64
- 14
- 27
- 8100
- 13
- 256
- 18
- 59
- 98
- 1444
- 54
- 57
- 7396
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