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 56²? =
- 2.What is 19²? =
- 3.What is the smallest whole number by which 56 must be multiplied to get a perfect square?
- 4.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 5.What is the smallest whole number by which 112 must be multiplied to get a perfect square?
- 6.What is 13²? =
- 7.How many whole numbers lie between 25² and 26²?
- 8.Which of these is a perfect square? (a) 431 (b) 423 (c) 400
- 9.How many whole numbers lie between 24² and 25²?
- 10.What is √3364? =
- 11.Which of these is a perfect square? (a) 169 (b) 190 (c) 173
- 12.What is 26²? =
- 13.What is the smallest whole number by which 320 must be divided to get a perfect square?
- 14.A square garden has an area of 1681 square m. How long is each side (in m)?
- 15.How many whole numbers lie between 46² and 47²?
- 16.Which of these is a perfect square? (a) 1537 (b) 1521 (c) 1534
- 17.A square garden has an area of 2601 square m. How long is each side (in m)?
- 18.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 19.What is √6400? =
- 20.What is 62²? =
- 21.What is √7569? =
- 22.What is √1296? =
- 23.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 24.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 25.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 26.How many whole numbers lie between 22² and 23²?
- 27.A square garden has an area of 841 square m. How long is each side (in m)?
- 28.Which of these is a perfect square? (a) 212 (b) 220 (c) 196
- 29.A square garden has an area of 441 square m. How long is each side (in m)?
- 30.What is the smallest whole number by which 135 must be multiplied to get a perfect square?
- 31.What is 21²? =
- 32.What is the smallest whole number by which 192 must be multiplied to get a perfect square?
- 33.What is 71²? =
- 34.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 35.What is 90²? =
- 36.A square garden has an area of 289 square m. How long is each side (in m)?
- 37.How many whole numbers lie between 21² and 22²?
- 38.How many whole numbers lie between 32² and 33²?
- 39.What is √3025? =
- 40.What is 70²? =
Answer key
- 3136
- 361
- 14
- 729
- 7
- 169
- 50
- 400
- 48
- 58
- 169
- 676
- 5
- 41
- 92
- 1521
- 51
- 400
- 80
- 3844
- 87
- 36
- 900
- 169
- 25
- 44
- 29
- 196
- 21
- 15
- 441
- 3
- 5041
- 576
- 8100
- 17
- 42
- 64
- 55
- 4900
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