A method of writing approximate forms of large numbers in which the magnitude is separated out of the number and expressed as a power of ten. For instance, 6.02 x 1023 is a short way of writing 602000000000000000000000.

Computers and some calculators often use a shorthand "e notation" for writing numbers in exponential notation in which the times sign and the 10 are replaced by a letter e (sometimes capitalized), so 6.02E23 for the number above. This is used in contexts where the superscript for the exponent cannot be produced.