← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 348 · 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 ∛9261? =
  2. 2.What is 19³? =
  3. 3.What is the smallest whole number by which 4 must be divided to get a perfect cube?
  4. 4.What is ∛27? =
  5. 5.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  6. 6.What is the smallest whole number by which 448 must be divided to get a perfect cube?
  7. 7.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  8. 8.What is 2³? =
  9. 9.What is the smallest whole number by which 1944 must be multiplied to get a perfect cube?
  10. 10.What is ∛125? =
  11. 11.What is ∛512? =
  12. 12.Which of these is a perfect cube? (a) 34 (b) 48 (c) 27
  13. 13.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  14. 14.What is 6³? =
  15. 15.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  16. 16.Which of these is a perfect cube? (a) 3433 (b) 3375 (c) 3379
  17. 17.Which of these is a perfect cube? (a) 773 (b) 920 (c) 729
  18. 18.What is 4³? =
  19. 19.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  20. 20.What is 5³? =
  21. 21.Which of these is a perfect cube? (a) 1743 (b) 1728 (c) 1758
  22. 22.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  23. 23.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
  24. 24.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  25. 25.What is the smallest whole number by which 875 must be divided to get a perfect cube?
  26. 26.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  27. 27.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  28. 28.What is 14³? =
  29. 29.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  30. 30.Which of these is a perfect cube? (a) 88 (b) 72 (c) 64
  31. 31.What is ∛4096? =
  32. 32.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  33. 33.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  34. 34.What is the smallest whole number by which 6125 must be multiplied to get a perfect cube?
  35. 35.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  36. 36.What is ∛6859? =
  37. 37.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  38. 38.What is ∛5832? =
  39. 39.What is the smallest whole number by which 32 must be multiplied to get a perfect cube?
  40. 40.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?

Answer key

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

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