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 96²? =
- 2.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 3.Which of these is a perfect square? (a) 948 (b) 953 (c) 900
- 4.What is √676? =
- 5.How many whole numbers lie between 15² and 16²?
- 6.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
- 7.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 8.What is the smallest whole number by which 891 must be divided to get a perfect square?
- 9.What is the smallest whole number by which 350 must be divided to get a perfect square?
- 10.How many whole numbers lie between 19² and 20²?
- 11.What is 62²? =
- 12.What is √2916? =
- 13.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 14.What is √8649? =
- 15.Which of these is a perfect square? (a) 361 (b) 367 (c) 376
- 16.What is 28²? =
- 17.A square garden has an area of 3600 square m. How long is each side (in m)?
- 18.Which of these is a perfect square? (a) 204 (b) 196 (c) 221
- 19.What is 42²? =
- 20.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 21.Which of these is a perfect square? (a) 1299 (b) 1296 (c) 1307
- 22.What is √3600? =
- 23.How many whole numbers lie between 38² and 39²?
- 24.Which of these is a perfect square? (a) 1369 (b) 1385 (c) 1391
- 25.What is √225? =
- 26.A square garden has an area of 196 square m. How long is each side (in m)?
- 27.What is 98²? =
- 28.A square garden has an area of 64 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 343 must be multiplied to get a perfect square?
- 30.What is 48²? =
- 31.How many whole numbers lie between 17² and 18²?
- 32.A square garden has an area of 1936 square m. How long is each side (in m)?
- 33.How many whole numbers lie between 34² and 35²?
- 34.What is 80²? =
- 35.Which of these is a perfect square? (a) 1030 (b) 1051 (c) 1024
- 36.Which of these is a perfect square? (a) 133 (b) 129 (c) 121
- 37.What is √6724? =
- 38.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 39.Which of these is a perfect square? (a) 655 (b) 625 (c) 650
- 40.What is the smallest whole number by which 135 must be divided to get a perfect square?
Answer key
- 9216
- 361
- 900
- 26
- 30
- 2
- 441
- 11
- 14
- 38
- 3844
- 54
- 5
- 93
- 361
- 784
- 60
- 196
- 1764
- 784
- 1296
- 60
- 76
- 1369
- 15
- 14
- 9604
- 8
- 7
- 2304
- 34
- 44
- 68
- 6400
- 1024
- 121
- 82
- 289
- 625
- 15
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