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 9 odd numbers (1 + 3 + 5 + …)?
- 2.A square garden has an area of 729 square m. How long is each side (in m)?
- 3.Which of these is a perfect square? (a) 1538 (b) 1521 (c) 1592
- 4.How many whole numbers lie between 34² and 35²?
- 5.What is √2704? =
- 6.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 7.What is 15²? =
- 8.What is the smallest whole number by which 896 must be multiplied to get a perfect square?
- 9.Which of these is a perfect square? (a) 496 (b) 484 (c) 494
- 10.What is the smallest whole number by which 150 must be divided to get a perfect square?
- 11.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 12.What is the smallest whole number by which 80 must be divided to get a perfect square?
- 13.How many whole numbers lie between 21² and 22²?
- 14.What is the smallest whole number by which 50 must be divided to get a perfect square?
- 15.What is 20²? =
- 16.What is the smallest whole number by which 1053 must be multiplied to get a perfect square?
- 17.What is √7569? =
- 18.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 19.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 20.Which of these is a perfect square? (a) 174 (b) 169 (c) 178
- 21.What is √1225? =
- 22.Which of these is a perfect square? (a) 225 (b) 235 (c) 247
- 23.What is √529? =
- 24.How many whole numbers lie between 18² and 19²?
- 25.A square garden has an area of 49 square m. How long is each side (in m)?
- 26.What is √2916? =
- 27.What is √8281? =
- 28.A square garden has an area of 2500 square m. How long is each side (in m)?
- 29.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 30.What is √9604? =
- 31.What is the smallest whole number by which 176 must be multiplied to get a perfect square?
- 32.What is the smallest whole number by which 325 must be multiplied to get a perfect square?
- 33.What is 45²? =
- 34.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 35.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 36.What is √3600? =
- 37.Which of these is a perfect square? (a) 209 (b) 196 (c) 199
- 38.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 39.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
- 40.What is the smallest whole number by which 275 must be multiplied to get a perfect square?
Answer key
- 81
- 27
- 1521
- 68
- 52
- 64
- 225
- 14
- 484
- 6
- 196
- 5
- 42
- 2
- 400
- 13
- 87
- 121
- 36
- 169
- 35
- 225
- 23
- 36
- 7
- 54
- 91
- 50
- 441
- 98
- 11
- 13
- 2025
- 25
- 100
- 60
- 196
- 361
- 14
- 11
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