← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 778 · 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 ∛8000? =
  2. 2.What is the smallest whole number by which 4 must be divided to get a perfect cube?
  3. 3.What is 19³? =
  4. 4.What is the smallest whole number by which 256 must be divided to get a perfect cube?
  5. 5.What is ∛9261? =
  6. 6.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  7. 7.What is ∛1728? =
  8. 8.Which of these is a perfect cube? (a) 1439 (b) 1571 (c) 1331
  9. 9.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  10. 10.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  11. 11.What is 2³? =
  12. 12.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  13. 13.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  14. 14.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  15. 15.What is 16³? =
  16. 16.What is ∛5832? =
  17. 17.What is ∛2197? =
  18. 18.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  19. 19.What is ∛2744? =
  20. 20.What is ∛64? =
  21. 21.What is 20³? =
  22. 22.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  23. 23.What is ∛216? =
  24. 24.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  25. 25.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  26. 26.Which of these is a perfect cube? (a) 454 (b) 343 (c) 344
  27. 27.What is ∛6859? =
  28. 28.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  29. 29.Which of these is a perfect cube? (a) 1728 (b) 1743 (c) 2057
  30. 30.Which of these is a perfect cube? (a) 3424 (b) 3959 (c) 3375
  31. 31.Which of these is a perfect cube? (a) 64 (b) 93 (c) 95
  32. 32.What is the smallest whole number by which 625 must be multiplied to get a perfect cube?
  33. 33.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  34. 34.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  35. 35.Which of these is a perfect cube? (a) 142 (b) 135 (c) 125
  36. 36.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  37. 37.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  38. 38.What is 4³? =
  39. 39.What is the smallest whole number by which 1125 must be divided to get a perfect cube?
  40. 40.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?

Answer key

  1. 20
  2. 4
  3. 6859
  4. 4
  5. 21
  6. 27
  7. 12
  8. 1331
  9. 25
  10. 3
  11. 8
  12. 9
  13. 15
  14. 8
  15. 4096
  16. 18
  17. 13
  18. 4
  19. 14
  20. 4
  21. 8000
  22. 18
  23. 6
  24. 216
  25. 125
  26. 343
  27. 19
  28. 17
  29. 1728
  30. 3375
  31. 64
  32. 25
  33. 8
  34. 6
  35. 125
  36. 4
  37. 64
  38. 64
  39. 9
  40. 12

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