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 18 odd numbers (1 + 3 + 5 + …)?
- 2.What is the smallest whole number by which 28 must be divided to get a perfect square?
- 3.What is √529? =
- 4.How many whole numbers lie between 50² and 51²?
- 5.What is the smallest whole number by which 896 must be divided to get a perfect square?
- 6.What is √2116? =
- 7.Which of these is a perfect square? (a) 144 (b) 152 (c) 148
- 8.A square garden has an area of 784 square m. How long is each side (in m)?
- 9.Which of these is a perfect square? (a) 336 (b) 324 (c) 327
- 10.What is √625? =
- 11.What is √8100? =
- 12.What is 75²? =
- 13.What is the smallest whole number by which 325 must be divided to get a perfect square?
- 14.What is 90²? =
- 15.Which of these is a perfect square? (a) 179 (b) 169 (c) 172
- 16.What is 38²? =
- 17.What is √4761? =
- 18.What is the smallest whole number by which 240 must be multiplied to get a perfect square?
- 19.How many whole numbers lie between 36² and 37²?
- 20.How many whole numbers lie between 48² and 49²?
- 21.What is the smallest whole number by which 72 must be divided to get a perfect square?
- 22.What is 82²? =
- 23.What is the smallest whole number by which 54 must be divided to get a perfect square?
- 24.What is the smallest whole number by which 640 must be divided to get a perfect square?
- 25.What is √324? =
- 26.How many whole numbers lie between 10² and 11²?
- 27.What is the smallest whole number by which 117 must be multiplied to get a perfect square?
- 28.A square garden has an area of 324 square m. How long is each side (in m)?
- 29.Which of these is a perfect square? (a) 578 (b) 576 (c) 622
- 30.What is 47²? =
- 31.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 32.What is √5476? =
- 33.Which of these is a perfect square? (a) 283 (b) 256 (c) 285
- 34.A square garden has an area of 1369 square m. How long is each side (in m)?
- 35.A square garden has an area of 400 square m. How long is each side (in m)?
- 36.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 37.What is √121? =
- 38.How many whole numbers lie between 13² and 14²?
- 39.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 40.What is 33²? =
Answer key
- 324
- 7
- 23
- 100
- 14
- 46
- 144
- 28
- 324
- 25
- 90
- 5625
- 13
- 8100
- 169
- 1444
- 69
- 15
- 72
- 96
- 2
- 6724
- 6
- 10
- 18
- 20
- 13
- 18
- 576
- 2209
- 441
- 74
- 256
- 37
- 20
- 3
- 11
- 26
- 64
- 1089
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