This video introduces to students what a variable, expression, and equation is. It also demonstrates how to substitute values for variables and evaluate expressions and equations using substitution. [6:55]

This video demonstrates how to solve a word problem using an expression and substituting values for a variable. [2:00]

This video lesson demonstrates how variables are used as placeholders in algebraic expressions. Students can check their understanding with an assessment.

Algebra and variables are defined and explained in this lesson. Take quiz to check understanding.

This QuickTime movie provides an opportunity to translate English words into an algebraic expression. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.