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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 450 · 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 20 must be multiplied to get a perfect square?
  2. 2.What is √1600? =
  3. 3.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  4. 4.Which of these is a perfect square? (a) 216 (b) 196 (c) 215
  5. 5.What is √4624? =
  6. 6.What is 49²? =
  7. 7.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is √576? =
  9. 9.A square garden has an area of 100 square m. How long is each side (in m)?
  10. 10.What is √5041? =
  11. 11.What is √900? =
  12. 12.What is 37²? =
  13. 13.What is √9025? =
  14. 14.A square garden has an area of 225 square m. How long is each side (in m)?
  15. 15.How many whole numbers lie between 5² and 6²?
  16. 16.What is the smallest whole number by which 99 must be divided to get a perfect square?
  17. 17.How many whole numbers lie between 33² and 34²?
  18. 18.What is √4225? =
  19. 19.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
  20. 20.Which of these is a perfect square? (a) 1434 (b) 1370 (c) 1369
  21. 21.What is 98²? =
  22. 22.What is √4356? =
  23. 23.What is the smallest whole number by which 224 must be divided to get a perfect square?
  24. 24.What is the smallest whole number by which 147 must be divided to get a perfect square?
  25. 25.What is √8649? =
  26. 26.How many whole numbers lie between 14² and 15²?
  27. 27.A square garden has an area of 81 square m. How long is each side (in m)?
  28. 28.What is √2116? =
  29. 29.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
  30. 30.How many whole numbers lie between 47² and 48²?
  31. 31.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  32. 32.What is 18²? =
  33. 33.What is √4489? =
  34. 34.A square garden has an area of 196 square m. How long is each side (in m)?
  35. 35.How many whole numbers lie between 29² and 30²?
  36. 36.A square garden has an area of 324 square m. How long is each side (in m)?
  37. 37.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
  38. 38.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  39. 39.Which of these is a perfect square? (a) 563 (b) 532 (c) 529
  40. 40.What is 40²? =

Answer key

  1. 5
  2. 40
  3. 784
  4. 196
  5. 68
  6. 2401
  7. 841
  8. 24
  9. 10
  10. 71
  11. 30
  12. 1369
  13. 95
  14. 15
  15. 10
  16. 11
  17. 66
  18. 65
  19. 225
  20. 1369
  21. 9604
  22. 66
  23. 14
  24. 3
  25. 93
  26. 28
  27. 9
  28. 46
  29. 576
  30. 94
  31. 529
  32. 324
  33. 67
  34. 14
  35. 58
  36. 18
  37. 81
  38. 36
  39. 529
  40. 1600

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