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 smallest whole number by which 147 must be divided to get a perfect square?
- 2.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 3.Which of these is a perfect square? (a) 1171 (b) 1202 (c) 1156
- 4.What is √576? =
- 5.What is 81²? =
- 6.What is √2209? =
- 7.What is the smallest whole number by which 180 must be divided to get a perfect square?
- 8.What is √1024? =
- 9.Which of these is a perfect square? (a) 144 (b) 147 (c) 150
- 10.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 11.Which of these is a perfect square? (a) 554 (b) 529 (c) 538
- 12.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 13.A square garden has an area of 900 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 900 (b) 918 (c) 902
- 15.A square garden has an area of 225 square m. How long is each side (in m)?
- 16.What is 60²? =
- 17.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 18.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 19.What is √676? =
- 20.A square garden has an area of 400 square m. How long is each side (in m)?
- 21.What is the smallest whole number by which 810 must be divided to get a perfect square?
- 22.A square garden has an area of 144 square m. How long is each side (in m)?
- 23.What is the smallest whole number by which 275 must be multiplied to get a perfect square?
- 24.What is √2500? =
- 25.A square garden has an area of 2209 square m. How long is each side (in m)?
- 26.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 27.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 28.A square garden has an area of 361 square m. How long is each side (in m)?
- 29.Which of these is a perfect square? (a) 125 (b) 136 (c) 121
- 30.What is 68²? =
- 31.What is 90²? =
- 32.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 33.How many whole numbers lie between 19² and 20²?
- 34.How many whole numbers lie between 31² and 32²?
- 35.Which of these is a perfect square? (a) 1600 (b) 1654 (c) 1663
- 36.What is 34²? =
- 37.What is 14²? =
- 38.What is 44²? =
- 39.A square garden has an area of 49 square m. How long is each side (in m)?
- 40.What is 69²? =
Answer key
- 3
- 25
- 1156
- 24
- 6561
- 47
- 5
- 32
- 144
- 121
- 529
- 361
- 30
- 900
- 15
- 3600
- 784
- 484
- 26
- 20
- 10
- 12
- 11
- 50
- 47
- 144
- 5
- 19
- 121
- 4624
- 8100
- 64
- 38
- 62
- 1600
- 1156
- 196
- 1936
- 7
- 4761
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