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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 596 · 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.What is 3³? =
  2. 2.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  3. 3.What is 6³? =
  4. 4.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  5. 5.What is ∛512? =
  6. 6.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  7. 7.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  8. 8.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  9. 9.What is ∛8? =
  10. 10.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  11. 11.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  12. 12.Which of these is a perfect cube? (a) 142 (b) 148 (c) 125
  13. 13.What is ∛729? =
  14. 14.What is the smallest whole number by which 500 must be multiplied to get a perfect cube?
  15. 15.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.What is 17³? =
  17. 17.What is 10³? =
  18. 18.What is 7³? =
  19. 19.What is the smallest whole number by which 392 must be divided to get a perfect cube?
  20. 20.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  21. 21.What is the smallest whole number by which 375 must be divided to get a perfect cube?
  22. 22.What is 19³? =
  23. 23.What is ∛15625? =
  24. 24.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  25. 25.What is 15³? =
  26. 26.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  27. 27.What is ∛2744? =
  28. 28.What is the smallest whole number by which 189 must be multiplied to get a perfect cube?
  29. 29.Which of these is a perfect cube? (a) 747 (b) 729 (c) 795
  30. 30.What is 12³? =
  31. 31.Which of these is a perfect cube? (a) 2744 (b) 3284 (c) 3231
  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.Which of these is a perfect cube? (a) 216 (b) 277 (c) 237
  34. 34.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  35. 35.Which of these is a perfect cube? (a) 100 (b) 75 (c) 64
  36. 36.What is ∛64? =
  37. 37.What is 5³? =
  38. 38.What is the smallest whole number by which 1080 must be multiplied to get a perfect cube?
  39. 39.What is ∛10648? =
  40. 40.What is ∛9261? =

Answer key

  1. 27
  2. 6
  3. 216
  4. 5
  5. 8
  6. 19
  7. 20
  8. 3
  9. 2
  10. 2
  11. 25
  12. 125
  13. 9
  14. 2
  15. 27
  16. 4913
  17. 1000
  18. 343
  19. 49
  20. 125
  21. 3
  22. 6859
  23. 25
  24. 7
  25. 3375
  26. 9
  27. 14
  28. 49
  29. 729
  30. 1728
  31. 2744
  32. 216
  33. 216
  34. 13
  35. 64
  36. 4
  37. 125
  38. 25
  39. 22
  40. 21

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