Adding and Subtracting Measurements on a Ruler

Описание: Adding and Subtracting Measurements on a Ruler. Part of the series: Mathematics: Basic Subtraction. When adding and subtracting measurements on a ruler you have to take into consideration the values of each unit of measurement. Learn about adding and subtracting measurements on a ruler with help from a mathematics educator in this free video clip. Read more: http://www.ehow.com/video_12200805_ad...