In the previous section, we expressed numbers as powers of 10. This is termed the base of the expression. However the base can be any number so that:
| 100 | = | 10 × 10 | = | 102 | Base 10: Power 2 |
| 16 | = | 2 × 2 × 2 × 2 | = | 24 | Base 2: Power 4 |
| 27 | = | 3 × 3 × 3 | = | 33 | Base 3: Power 3 |
| 625 | = | 5 × 5 × 5 × 5 | = | 54 | Base 5: Power 4 |
and so on …
In power notation (also called scientific notation) any number can be represented as a power of 10 so that:
325 is between 100 (102) and 1 000 (103) and is equal to 3.25 × 100 = 3.25 × 102
625 400 is between 105 and 106 and is equal to 6.254 × 105
There are two special cases of powers. Any number raised to the power of 1 is itself, and any number raised to the power 0 equals 1.