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2. Powers and bases

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.