← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 149 · 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 ∛2744? =
  2. 2.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
  3. 3.Which of these is a perfect cube? (a) 1331 (b) 1345 (c) 1595
  4. 4.What is ∛3375? =
  5. 5.What is ∛1000? =
  6. 6.Which of these is a perfect cube? (a) 1757 (b) 1781 (c) 1728
  7. 7.What is the smallest whole number by which 189 must be divided to get a perfect cube?
  8. 8.What is ∛13824? =
  9. 9.What is 20³? =
  10. 10.What is ∛64? =
  11. 11.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  12. 12.What is ∛512? =
  13. 13.What is ∛27? =
  14. 14.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  15. 15.What is the smallest whole number by which 1600 must be divided to get a perfect cube?
  16. 16.What is the smallest whole number by which 432 must be divided to get a perfect cube?
  17. 17.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  18. 18.What is ∛15625? =
  19. 19.What is the smallest whole number by which 675 must be multiplied to get a perfect cube?
  20. 20.Which of these is a perfect cube? (a) 455 (b) 472 (c) 343
  21. 21.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  22. 22.What is the smallest whole number by which 135 must be divided to get a perfect cube?
  23. 23.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  24. 24.What is ∛10648? =
  25. 25.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  26. 26.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  27. 27.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  28. 28.Which of these is a perfect cube? (a) 27 (b) 37 (c) 36
  29. 29.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  30. 30.What is 12³? =
  31. 31.What is ∛12167? =
  32. 32.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  33. 33.What is 8³? =
  34. 34.What is ∛1331? =
  35. 35.What is 5³? =
  36. 36.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  37. 37.Which of these is a perfect cube? (a) 590 (b) 680 (c) 512
  38. 38.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  39. 39.What is the smallest whole number by which 49 must be divided to get a perfect cube?
  40. 40.Which of these is a perfect cube? (a) 1041 (b) 1168 (c) 1000

Answer key

  1. 14
  2. 9
  3. 1331
  4. 15
  5. 10
  6. 1728
  7. 7
  8. 24
  9. 8000
  10. 4
  11. 27
  12. 8
  13. 3
  14. 8
  15. 25
  16. 2
  17. 64
  18. 25
  19. 5
  20. 343
  21. 20
  22. 5
  23. 9
  24. 22
  25. 27
  26. 8
  27. 216
  28. 27
  29. 216
  30. 1728
  31. 23
  32. 8
  33. 512
  34. 11
  35. 125
  36. 125
  37. 512
  38. 4
  39. 49
  40. 1000

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