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.