Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 537 · 40 sums

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.

1. 1.What is 16³? =
2. 2.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
3. 3.What is ∛125? =
4. 4.What is the smallest whole number by which 1323 must be divided to get a perfect cube?
5. 5.What is 3³? =
6. 6.What is ∛343? =
7. 7.What is 12³? =
8. 8.Which of these is a perfect cube? (a) 1000 (b) 1089 (c) 1003
9. 9.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
10. 10.What is ∛13824? =
11. 11.Which of these is a perfect cube? (a) 2754 (b) 3260 (c) 2744
12. 12.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
13. 13.What is ∛1331? =
14. 14.What is the smallest whole number by which 81 must be divided to get a perfect cube?
15. 15.What is 20³? =
16. 16.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
17. 17.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
18. 18.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
19. 19.What is 4³? =
20. 20.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
21. 21.Which of these is a perfect cube? (a) 1690 (b) 1331 (c) 1411
22. 22.What is ∛15625? =
23. 23.What is 8³? =
24. 24.What is 15³? =
25. 25.What is ∛1000? =
26. 26.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
27. 27.What is 17³? =
28. 28.What is ∛216? =
29. 29.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
30. 30.What is 9³? =
31. 31.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
32. 32.What is ∛4096? =
33. 33.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
34. 34.What is the smallest whole number by which 200 must be divided to get a perfect cube?
35. 35.What is ∛512? =
36. 36.Which of these is a perfect cube? (a) 200 (b) 128 (c) 125
37. 37.What is ∛12167? =
38. 38.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
39. 39.What is the smallest whole number by which 500 must be divided to get a perfect cube?
40. 40.What is the smallest whole number by which 625 must be multiplied to get a perfect cube?

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