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 24 odd numbers (1 + 3 + 5 + …)?
- 2.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 3.How many whole numbers lie between 35² and 36²?
- 4.What is 84²? =
- 5.What is 47²? =
- 6.What is the smallest whole number by which 405 must be divided to get a perfect square?
- 7.What is √5776? =
- 8.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 9.A square garden has an area of 484 square m. How long is each side (in m)?
- 10.How many whole numbers lie between 32² and 33²?
- 11.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 12.A square garden has an area of 625 square m. How long is each side (in m)?
- 13.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 14.What is 55²? =
- 15.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 16.What is 22²? =
- 17.What is 76²? =
- 18.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
- 19.What is the smallest whole number by which 192 must be multiplied to get a perfect square?
- 20.How many whole numbers lie between 25² and 26²?
- 21.Which of these is a perfect square? (a) 1597 (b) 1521 (c) 1580
- 22.How many whole numbers lie between 14² and 15²?
- 23.How many whole numbers lie between 26² and 27²?
- 24.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 25.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 26.How many whole numbers lie between 34² and 35²?
- 27.A square garden has an area of 1024 square m. How long is each side (in m)?
- 28.A square garden has an area of 100 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 75 must be divided to get a perfect square?
- 30.How many whole numbers lie between 9² and 10²?
- 31.How many whole numbers lie between 10² and 11²?
- 32.What is 59²? =
- 33.A square garden has an area of 961 square m. How long is each side (in m)?
- 34.How many whole numbers lie between 8² and 9²?
- 35.How many whole numbers lie between 21² and 22²?
- 36.What is √6084? =
- 37.What is 26²? =
- 38.Which of these is a perfect square? (a) 100 (b) 115 (c) 103
- 39.What is 34²? =
- 40.What is √1444? =
Answer key
- 576
- 625
- 70
- 7056
- 2209
- 5
- 76
- 100
- 22
- 64
- 441
- 25
- 400
- 3025
- 289
- 484
- 5776
- 14
- 3
- 50
- 1521
- 28
- 52
- 144
- 121
- 68
- 32
- 10
- 3
- 18
- 20
- 3481
- 31
- 16
- 42
- 78
- 676
- 100
- 1156
- 38
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