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.A square garden has an area of 441 square m. How long is each side (in m)?
- 2.What is 47²? =
- 3.How many whole numbers lie between 26² and 27²?
- 4.What is the smallest whole number by which 175 must be divided to get a perfect square?
- 5.Which of these is a perfect square? (a) 303 (b) 321 (c) 289
- 6.What is 15²? =
- 7.A square garden has an area of 3136 square m. How long is each side (in m)?
- 8.Which of these is a perfect square? (a) 159 (b) 145 (c) 144
- 9.How many whole numbers lie between 12² and 13²?
- 10.Which of these is a perfect square? (a) 1604 (b) 1643 (c) 1600
- 11.What is √400? =
- 12.What is the smallest whole number by which 243 must be divided to get a perfect square?
- 13.A square garden has an area of 196 square m. How long is each side (in m)?
- 14.What is 36²? =
- 15.A square garden has an area of 2916 square m. How long is each side (in m)?
- 16.What is √841? =
- 17.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 18.What is the smallest whole number by which 112 must be multiplied to get a perfect square?
- 19.What is √1024? =
- 20.What is √441? =
- 21.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 22.What is the smallest whole number by which 48 must be divided to get a perfect square?
- 23.How many whole numbers lie between 36² and 37²?
- 24.What is √6561? =
- 25.Which of these is a perfect square? (a) 169 (b) 187 (c) 179
- 26.What is 31²? =
- 27.What is the smallest whole number by which 60 must be divided to get a perfect square?
- 28.A square garden has an area of 36 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 13² and 14²?
- 30.What is 88²? =
- 31.How many whole numbers lie between 49² and 50²?
- 32.What is the smallest whole number by which 320 must be multiplied to get a perfect square?
- 33.A square garden has an area of 529 square m. How long is each side (in m)?
- 34.A square garden has an area of 25 square m. How long is each side (in m)?
- 35.What is the smallest whole number by which 384 must be multiplied to get a perfect square?
- 36.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 37.What is the smallest whole number by which 180 must be divided to get a perfect square?
- 38.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 39.What is 84²? =
- 40.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
Answer key
- 21
- 2209
- 52
- 7
- 289
- 225
- 56
- 144
- 24
- 1600
- 20
- 3
- 14
- 1296
- 54
- 29
- 361
- 7
- 32
- 21
- 576
- 3
- 72
- 81
- 169
- 961
- 15
- 6
- 26
- 7744
- 98
- 5
- 23
- 5
- 6
- 441
- 5
- 144
- 7056
- 256
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