← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 7 · 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 13³? =
  2. 2.What is the smallest whole number by which 32 must be divided to get a perfect cube?
  3. 3.What is ∛3375? =
  4. 4.Which of these is a perfect cube? (a) 1595 (b) 1331 (c) 1530
  5. 5.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  6. 6.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  7. 7.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  8. 8.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  9. 9.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  10. 10.Which of these is a perfect cube? (a) 784 (b) 729 (c) 857
  11. 11.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  12. 12.What is 18³? =
  13. 13.What is 14³? =
  14. 14.What is 20³? =
  15. 15.What is the smallest whole number by which 40 must be divided to get a perfect cube?
  16. 16.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  17. 17.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  18. 18.What is the smallest whole number by which 3125 must be divided to get a perfect cube?
  19. 19.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  20. 20.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  21. 21.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  22. 22.What is the smallest whole number by which 16 must be divided to get a perfect cube?
  23. 23.What is the smallest whole number by which 576 must be divided to get a perfect cube?
  24. 24.Which of these is a perfect cube? (a) 477 (b) 478 (c) 343
  25. 25.What is ∛2744? =
  26. 26.What is 17³? =
  27. 27.What is the smallest whole number by which 3136 must be multiplied to get a perfect cube?
  28. 28.What is ∛8000? =
  29. 29.Which of these is a perfect cube? (a) 537 (b) 512 (c) 535
  30. 30.Which of these is a perfect cube? (a) 218 (b) 216 (c) 241
  31. 31.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
  32. 32.Which of these is a perfect cube? (a) 2403 (b) 2682 (c) 2197
  33. 33.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  34. 34.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  35. 35.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  36. 36.What is ∛5832? =
  37. 37.What is ∛13824? =
  38. 38.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  39. 39.What is ∛512? =
  40. 40.What is 2³? =

Answer key

  1. 2197
  2. 4
  3. 15
  4. 1331
  5. 5
  6. 5
  7. 25
  8. 9
  9. 64
  10. 729
  11. 8
  12. 5832
  13. 2744
  14. 8000
  15. 5
  16. 7
  17. 125
  18. 25
  19. 6
  20. 216
  21. 27
  22. 2
  23. 9
  24. 343
  25. 14
  26. 4913
  27. 7
  28. 20
  29. 512
  30. 216
  31. 9
  32. 2197
  33. 25
  34. 27
  35. 3
  36. 18
  37. 24
  38. 2
  39. 8
  40. 8

Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets