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 400 square m. How long is each side (in m)?
- 2.What is √8836? =
- 3.How many whole numbers lie between 9² and 10²?
- 4.Which of these is a perfect square? (a) 823 (b) 815 (c) 784
- 5.What is the smallest whole number by which 208 must be divided to get a perfect square?
- 6.What is √400? =
- 7.What is √1225? =
- 8.How many whole numbers lie between 7² and 8²?
- 9.What is 97²? =
- 10.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 11.What is the smallest whole number by which 32 must be divided to get a perfect square?
- 12.Which of these is a perfect square? (a) 256 (b) 271 (c) 257
- 13.What is √2025? =
- 14.What is √4624? =
- 15.What is √1681? =
- 16.What is the smallest whole number by which 486 must be divided to get a perfect square?
- 17.What is 19²? =
- 18.What is √5476? =
- 19.What is the smallest whole number by which 108 must be multiplied to get a perfect square?
- 20.Which of these is a perfect square? (a) 497 (b) 484 (c) 492
- 21.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 22.What is the smallest whole number by which 540 must be multiplied to get a perfect square?
- 23.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 24.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 25.Which of these is a perfect square? (a) 1067 (b) 1024 (c) 1071
- 26.How many whole numbers lie between 39² and 40²?
- 27.What is 74²? =
- 28.What is √6241? =
- 29.What is √841? =
- 30.A square garden has an area of 64 square m. How long is each side (in m)?
- 31.Which of these is a perfect square? (a) 104 (b) 108 (c) 100
- 32.Which of these is a perfect square? (a) 1467 (b) 1478 (c) 1444
- 33.What is 67²? =
- 34.How many whole numbers lie between 24² and 25²?
- 35.Which of these is a perfect square? (a) 1369 (b) 1384 (c) 1439
- 36.How many whole numbers lie between 15² and 16²?
- 37.What is the smallest whole number by which 54 must be multiplied to get a perfect square?
- 38.What is the smallest whole number by which 180 must be multiplied to get a perfect square?
- 39.What is the smallest whole number by which 48 must be divided to get a perfect square?
- 40.What is the smallest whole number by which 252 must be divided to get a perfect square?
Answer key
- 20
- 94
- 18
- 784
- 13
- 20
- 35
- 14
- 9409
- 25
- 2
- 256
- 45
- 68
- 41
- 6
- 361
- 74
- 3
- 484
- 361
- 15
- 49
- 225
- 1024
- 78
- 5476
- 79
- 29
- 8
- 100
- 1444
- 4489
- 48
- 1369
- 30
- 6
- 5
- 3
- 7
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets