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 12 odd numbers (1 + 3 + 5 + …)?
- 2.A square garden has an area of 1225 square m. How long is each side (in m)?
- 3.What is 73²? =
- 4.What is 20²? =
- 5.A square garden has an area of 36 square m. How long is each side (in m)?
- 6.A square garden has an area of 1296 square m. How long is each side (in m)?
- 7.A square garden has an area of 144 square m. How long is each side (in m)?
- 8.A square garden has an area of 841 square m. How long is each side (in m)?
- 9.Which of these is a perfect square? (a) 797 (b) 801 (c) 784
- 10.How many whole numbers lie between 28² and 29²?
- 11.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 12.Which of these is a perfect square? (a) 1444 (b) 1515 (c) 1489
- 13.What is the smallest whole number by which 80 must be divided to get a perfect square?
- 14.Which of these is a perfect square? (a) 729 (b) 760 (c) 746
- 15.What is the smallest whole number by which 160 must be multiplied to get a perfect square?
- 16.Which of these is a perfect square? (a) 1009 (b) 961 (c) 1014
- 17.What is the smallest whole number by which 24 must be multiplied to get a perfect square?
- 18.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 19.What is the smallest whole number by which 891 must be divided to get a perfect square?
- 20.How many whole numbers lie between 42² and 43²?
- 21.What is √900? =
- 22.What is 56²? =
- 23.How many whole numbers lie between 21² and 22²?
- 24.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 25.How many whole numbers lie between 13² and 14²?
- 26.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 27.What is the smallest whole number by which 468 must be divided to get a perfect square?
- 28.What is 19²? =
- 29.A square garden has an area of 196 square m. How long is each side (in m)?
- 30.Which of these is a perfect square? (a) 631 (b) 625 (c) 626
- 31.What is the smallest whole number by which 60 must be divided to get a perfect square?
- 32.What is 35²? =
- 33.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 34.What is the smallest whole number by which 490 must be divided to get a perfect square?
- 35.What is √1369? =
- 36.How many whole numbers lie between 18² and 19²?
- 37.How many whole numbers lie between 22² and 23²?
- 38.What is 44²? =
- 39.A square garden has an area of 324 square m. How long is each side (in m)?
- 40.What is √6724? =
Answer key
- 144
- 35
- 5329
- 400
- 6
- 36
- 12
- 29
- 784
- 56
- 784
- 1444
- 5
- 729
- 10
- 961
- 6
- 484
- 11
- 84
- 30
- 3136
- 42
- 900
- 26
- 121
- 13
- 361
- 14
- 625
- 15
- 1225
- 25
- 10
- 37
- 36
- 44
- 1936
- 18
- 82
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