It means use an exponent to represent the product of 10s necessary to obtain the number you are interested in. Examples 10*10*10*10*10 = 100,000 = 105 = 10^5 (Ten to the 5th power. There are 5 tens in the product.) 10*10 = 100 = 102 = 10^2 (Ten to the 2nd power. There are 2 tens in the product.) 10 = 10^1 1 = 10^0 (This is a matter of definition. It is consistent with the rules for exponents.) 0.1 = 1/10 = 10^(-1) (A negative power is the reciprocal of a positive power.) 0.01 = 1/100 = 10^(-2)