This document discusses multiplying and dividing by powers of ten. [1] It provides examples of multiplying whole numbers and decimals by powers of ten, which involves moving the decimal point right or left. [2] Rules are given that multiplying a number by a whole number power of ten moves the decimal right, while multiplying by a decimal power of ten moves the decimal left. [3] Dividing by powers of ten follows the same rules but in reverse - dividing by a whole number power of ten moves the decimal left, and dividing by a decimal power moves it right.