.1239
A decimal represents a value out of a whole, the "." representing everything under the amount of a whole (1). A percentage is essentially the same thing, except the "%" sign basically replaces the decimal. To convert a percentage to a decimal, move the decimal (and if there isn't one, add one to the right of the last number). Then, move that decimal two places to the right. For every empty space you move, add a zero there.
