Standard form, or scientific notation, writes a number as $a imes 10^n$, where $1 le a < 10$ and $n$ is an integer.

This makes very large and very small values easier to read, compare, and reuse in science or engineering work.

A positive exponent means the decimal moved left in the original number to produce a coefficient between 1 and 10. A negative exponent means the decimal moved right.

Example: $0.00456 = 4.56 imes 10^{-3}$.