← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 55 · 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 ∛512? =
  2. 2.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  3. 3.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  4. 4.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  5. 5.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  6. 6.Which of these is a perfect cube? (a) 2541 (b) 2197 (c) 2683
  7. 7.What is the smallest whole number by which 9 must be multiplied to get a perfect cube?
  8. 8.What is 3³? =
  9. 9.What is 8³? =
  10. 10.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  11. 11.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  12. 12.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  13. 13.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  14. 14.What is the smallest whole number by which 6125 must be divided to get a perfect cube?
  15. 15.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  16. 16.What is ∛1728? =
  17. 17.A cube has a volume of 1000 cubic cm. How long is each edge (in cm)?
  18. 18.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  19. 19.What is the smallest whole number by which 10584 must be multiplied to get a perfect cube?
  20. 20.What is ∛125? =
  21. 21.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  22. 22.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  23. 23.What is 18³? =
  24. 24.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  25. 25.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  26. 26.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  27. 27.What is the smallest whole number by which 108 must be divided to get a perfect cube?
  28. 28.Which of these is a perfect cube? (a) 446 (b) 402 (c) 343
  29. 29.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  30. 30.What is 14³? =
  31. 31.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  32. 32.What is ∛343? =
  33. 33.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  34. 34.Which of these is a perfect cube? (a) 4004 (b) 3706 (c) 3375
  35. 35.What is 4³? =
  36. 36.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  37. 37.Which of these is a perfect cube? (a) 2103 (b) 1917 (c) 1728
  38. 38.What is ∛4096? =
  39. 39.What is ∛15625? =
  40. 40.What is the smallest whole number by which 5 must be divided to get a perfect cube?

Answer key

  1. 8
  2. 8
  3. 64
  4. 125
  5. 7
  6. 2197
  7. 3
  8. 27
  9. 512
  10. 27
  11. 64
  12. 25
  13. 216
  14. 49
  15. 14
  16. 12
  17. 10
  18. 18
  19. 7
  20. 5
  21. 216
  22. 125
  23. 5832
  24. 8
  25. 12
  26. 216
  27. 4
  28. 343
  29. 6
  30. 2744
  31. 2
  32. 7
  33. 27
  34. 3375
  35. 64
  36. 5
  37. 1728
  38. 16
  39. 25
  40. 5

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