Cube And Cube Roots

 

How to Cube A Number

To cube a number, just use it in a multiplication 3 times ...

Example: What is 4 Cubed?

3 Cubed

=

cube root symbol

 

 

=

4 × 4 × 4

= 64

Cubes From 03 to 73

0 cubed

=

03

=

0 × 0 × 0

=

0

1 cubed

=

13

=

1 × 1 × 1

=

1

2 cubed

=

23

=

2 × 2 × 2

=

8

3 cubed

=

33

=

3 × 3 × 3

=

27

4 cubed

=

43

=

4 × 4 × 4

=

64

5 cubed

=

53

=

5 × 5 × 5

=

125

6 cubed

=

63

=

6 × 6 × 6

=

216

7 cubed

=

73

=

7 × 7 × 7

=

343

Cube Root

cube root goes the other direction:

3 cubed is 27, so the cube root of 27 is 3

 

The cube root of a number is ...
... a special value that when cubed gives the original number.

The cube root of 27 is ...
... 3, because when 3 is cubed you get 27

Example: What is the Cube root of 125?

We know that 125 = 5 × 5 × 5 , so cube root of 125 is 5

The Cube Root Symbol

 

cube root symbol

This is the special symbol that means "cube root", it is the "radical" symbol (used for square roots) with a little three to mean cube root.

When we cube negative numbers, answer is in negative.

When we cube +5 we get +125:+5 × +5 × +5 = +125

When we cube −5 we get −125:−5 × −5 × −5 = −125

So the cube root of −125 is −5