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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 284 · 40 sums
TalentJR

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. 1.What is the smallest whole number by which 1053 must be divided to get a perfect square?
  2. 2.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
  3. 3.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  4. 4.What is √2704? =
  5. 5.How many whole numbers lie between 20² and 21²?
  6. 6.Which of these is a perfect square? (a) 1123 (b) 1089 (c) 1098
  7. 7.How many whole numbers lie between 35² and 36²?
  8. 8.What is the smallest whole number by which 1134 must be divided to get a perfect square?
  9. 9.A square garden has an area of 2025 square m. How long is each side (in m)?
  10. 10.What is 87²? =
  11. 11.What is √324? =
  12. 12.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
  13. 13.Which of these is a perfect square? (a) 256 (b) 284 (c) 272
  14. 14.What is √2809? =
  15. 15.What is 51²? =
  16. 16.What is 86²? =
  17. 17.What is the smallest whole number by which 135 must be multiplied to get a perfect square?
  18. 18.What is √1849? =
  19. 19.What is √484? =
  20. 20.What is √9025? =
  21. 21.What is the smallest whole number by which 325 must be multiplied to get a perfect square?
  22. 22.What is the smallest whole number by which 240 must be divided to get a perfect square?
  23. 23.How many whole numbers lie between 19² and 20²?
  24. 24.Which of these is a perfect square? (a) 250 (b) 225 (c) 231
  25. 25.Which of these is a perfect square? (a) 327 (b) 324 (c) 329
  26. 26.What is the smallest whole number by which 320 must be multiplied to get a perfect square?
  27. 27.What is 42²? =
  28. 28.What is 20²? =
  29. 29.What is 24²? =
  30. 30.How many whole numbers lie between 34² and 35²?
  31. 31.How many whole numbers lie between 36² and 37²?
  32. 32.What is the smallest whole number by which 384 must be divided to get a perfect square?
  33. 33.What is the smallest whole number by which 99 must be multiplied to get a perfect square?
  34. 34.What is the smallest whole number by which 375 must be divided to get a perfect square?
  35. 35.What is √1089? =
  36. 36.What is 97²? =
  37. 37.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
  38. 38.What is √6241? =
  39. 39.What is the smallest whole number by which 28 must be divided to get a perfect square?
  40. 40.What is the smallest whole number by which 48 must be divided to get a perfect square?

Answer key

  1. 13
  2. 324
  3. 49
  4. 52
  5. 40
  6. 1089
  7. 70
  8. 14
  9. 45
  10. 7569
  11. 18
  12. 100
  13. 256
  14. 53
  15. 2601
  16. 7396
  17. 15
  18. 43
  19. 22
  20. 95
  21. 13
  22. 15
  23. 38
  24. 225
  25. 324
  26. 5
  27. 1764
  28. 400
  29. 576
  30. 68
  31. 72
  32. 6
  33. 11
  34. 15
  35. 33
  36. 9409
  37. 576
  38. 79
  39. 7
  40. 3

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