# Powers of 10

Students learn that a power of ten is an expression written in exponential form that has a base of ten. For example, 10^3 and 10^(-4) are powers of ten. To write a power of ten, such as 10^3, in standard form, begin with 1.0. Next, since the exponent on the power of ten is positive, move the decimal point to the right 3 places, to get 1000. So 10^3 in standard form is 1000. Note that if the exponent on the power of ten is negative, the decimal on the 1.0 is moved to the left. Students also learn to write a number as a power of ten, such as 0.0000001, by determining the number of places the decimal must be moved to get 1.0, which in this case is 7 places. Next, since the original number is a decimal, the exponent will be negative, so the answer is 10^(-7). Note that if the original number is a whole number, then the exponent will be positive.