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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 475 · 40 sums
TalentJR

The method (Threes make cubes): Cube: n × n × n. Cube root: the number that, used three times, gives the cube. Units digits: 1→1, 2→8, 3→7, 4→4, 5→5, 6→6, 7→3, 8→2, 9→9, 0→0 — use them to guess cube roots. Make a perfect cube: break into primes; multiply by what completes each group of three (or divide by what is left over). A big cube of edge a cut into small cubes of edge b gives (a ÷ b)³ small cubes.

NameDateTime takenScore ___ / 40
  1. 1.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  2. 2.Which of these is a perfect cube? (a) 28 (b) 37 (c) 27
  3. 3.What is 9³? =
  4. 4.Which of these is a perfect cube? (a) 729 (b) 730 (c) 738
  5. 5.What is ∛8? =
  6. 6.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  7. 7.What is 17³? =
  8. 8.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  9. 9.Which of these is a perfect cube? (a) 3375 (b) 4008 (c) 3450
  10. 10.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  11. 11.What is ∛125? =
  12. 12.Which of these is a perfect cube? (a) 1728 (b) 2075 (c) 2094
  13. 13.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  14. 14.Which of these is a perfect cube? (a) 2979 (b) 2794 (c) 2744
  15. 15.What is 15³? =
  16. 16.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  17. 17.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  18. 18.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  19. 19.What is ∛8000? =
  20. 20.What is 14³? =
  21. 21.What is 11³? =
  22. 22.What is 4³? =
  23. 23.What is the smallest whole number by which 1512 must be multiplied to get a perfect cube?
  24. 24.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  25. 25.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  26. 26.What is the smallest whole number by which 6125 must be divided to get a perfect cube?
  27. 27.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  28. 28.What is ∛5832? =
  29. 29.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  30. 30.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  31. 31.What is ∛13824? =
  32. 32.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  33. 33.What is 2³? =
  34. 34.What is the smallest whole number by which 56 must be multiplied to get a perfect cube?
  35. 35.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  36. 36.What is 8³? =
  37. 37.What is the smallest whole number by which 1080 must be multiplied to get a perfect cube?
  38. 38.What is the smallest whole number by which 200 must be multiplied to get a perfect cube?
  39. 39.What is ∛343? =
  40. 40.What is 7³? =

Answer key

  1. 14
  2. 27
  3. 729
  4. 729
  5. 2
  6. 9
  7. 4913
  8. 125
  9. 3375
  10. 2
  11. 5
  12. 1728
  13. 27
  14. 2744
  15. 3375
  16. 12
  17. 216
  18. 5
  19. 20
  20. 2744
  21. 1331
  22. 64
  23. 49
  24. 25
  25. 2
  26. 49
  27. 4
  28. 18
  29. 18
  30. 64
  31. 24
  32. 216
  33. 8
  34. 49
  35. 20
  36. 512
  37. 25
  38. 5
  39. 7
  40. 343

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