A method of expressing numbers in terms of powers of ten, useful for expressing very small or very large numbers. For example, 6.02E23, means 6.02 times ten to the 23rd power. (The letter E stands for exponent.)  The number is easier to understand in this form than in the form 602000000000000000000000. Applesoft BASIC uses this method to display real (floating-point) numbers with more than nine digits.