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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 256 · 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 sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  2. 2.What is 96²? =
  3. 3.What is the smallest whole number by which 360 must be divided to get a perfect square?
  4. 4.What is the smallest whole number by which 540 must be multiplied to get a perfect square?
  5. 5.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  6. 6.What is √144? =
  7. 7.What is √1296? =
  8. 8.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
  9. 9.What is the smallest whole number by which 686 must be divided to get a perfect square?
  10. 10.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
  11. 11.How many whole numbers lie between 9² and 10²?
  12. 12.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  13. 13.A square garden has an area of 169 square m. How long is each side (in m)?
  14. 14.What is √6561? =
  15. 15.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
  16. 16.What is 70²? =
  17. 17.How many whole numbers lie between 31² and 32²?
  18. 18.How many whole numbers lie between 39² and 40²?
  19. 19.What is the smallest whole number by which 56 must be divided to get a perfect square?
  20. 20.How many whole numbers lie between 43² and 44²?
  21. 21.What is √1089? =
  22. 22.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  23. 23.Which of these is a perfect square? (a) 1629 (b) 1600 (c) 1636
  24. 24.How many whole numbers lie between 20² and 21²?
  25. 25.What is 34²? =
  26. 26.How many whole numbers lie between 10² and 11²?
  27. 27.What is 97²? =
  28. 28.A square garden has an area of 1225 square m. How long is each side (in m)?
  29. 29.What is √9216? =
  30. 30.What is 62²? =
  31. 31.A square garden has an area of 361 square m. How long is each side (in m)?
  32. 32.What is 48²? =
  33. 33.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
  34. 34.What is 92²? =
  35. 35.A square garden has an area of 121 square m. How long is each side (in m)?
  36. 36.What is √7744? =
  37. 37.A square garden has an area of 2704 square m. How long is each side (in m)?
  38. 38.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
  39. 39.A square garden has an area of 1600 square m. How long is each side (in m)?
  40. 40.What is √2809? =

Answer key

  1. 144
  2. 9216
  3. 10
  4. 15
  5. 121
  6. 12
  7. 36
  8. 14
  9. 14
  10. 256
  11. 18
  12. 784
  13. 13
  14. 81
  15. 225
  16. 4900
  17. 62
  18. 78
  19. 14
  20. 86
  21. 33
  22. 900
  23. 1600
  24. 40
  25. 1156
  26. 20
  27. 9409
  28. 35
  29. 96
  30. 3844
  31. 19
  32. 2304
  33. 2
  34. 8464
  35. 11
  36. 88
  37. 52
  38. 441
  39. 40
  40. 53

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