## Precalculus (6th Edition) Blitzer

a number which is greater or equal to 1 and less than 10; $integer$.
Step 1. A scientific notation $a\times10^n$ requires that $1\leq |a| \lt 10$ and $n$ is an integer. Step 2. For a positive number in the above form, $a$ is a positive number $1\leq a \lt 10$ and $n$ is an integer.