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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 39 · 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 √1764? =
  2. 2.What is the smallest whole number by which 126 must be multiplied to get a perfect square?
  3. 3.What is √4624? =
  4. 4.A square garden has an area of 1444 square m. How long is each side (in m)?
  5. 5.What is √3969? =
  6. 6.What is 71²? =
  7. 7.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is √5184? =
  9. 9.What is 37²? =
  10. 10.What is 26²? =
  11. 11.A square garden has an area of 784 square m. How long is each side (in m)?
  12. 12.How many whole numbers lie between 9² and 10²?
  13. 13.What is √484? =
  14. 14.What is √7056? =
  15. 15.What is the smallest whole number by which 45 must be divided to get a perfect square?
  16. 16.What is 79²? =
  17. 17.What is √3364? =
  18. 18.How many whole numbers lie between 6² and 7²?
  19. 19.What is 43²? =
  20. 20.What is √9801? =
  21. 21.What is 54²? =
  22. 22.A square garden has an area of 2304 square m. How long is each side (in m)?
  23. 23.How many whole numbers lie between 38² and 39²?
  24. 24.A square garden has an area of 1225 square m. How long is each side (in m)?
  25. 25.What is 17²? =
  26. 26.Which of these is a perfect square? (a) 925 (b) 936 (c) 900
  27. 27.How many whole numbers lie between 37² and 38²?
  28. 28.A square garden has an area of 49 square m. How long is each side (in m)?
  29. 29.What is 34²? =
  30. 30.A square garden has an area of 100 square m. How long is each side (in m)?
  31. 31.What is 15²? =
  32. 32.What is 83²? =
  33. 33.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
  34. 34.How many whole numbers lie between 31² and 32²?
  35. 35.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  36. 36.How many whole numbers lie between 12² and 13²?
  37. 37.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  38. 38.How many whole numbers lie between 11² and 12²?
  39. 39.Which of these is a perfect square? (a) 1158 (b) 1156 (c) 1206
  40. 40.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?

Answer key

  1. 42
  2. 14
  3. 68
  4. 38
  5. 63
  6. 5041
  7. 900
  8. 72
  9. 1369
  10. 676
  11. 28
  12. 18
  13. 22
  14. 84
  15. 5
  16. 6241
  17. 58
  18. 12
  19. 1849
  20. 99
  21. 2916
  22. 48
  23. 76
  24. 35
  25. 289
  26. 900
  27. 74
  28. 7
  29. 1156
  30. 10
  31. 225
  32. 6889
  33. 400
  34. 62
  35. 784
  36. 24
  37. 36
  38. 22
  39. 1156
  40. 64

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