This video demonstrates how to solve a word problem by calculating rates. The video uses the formula for distance and isolates the variable "r" for rate. Practice problems available. [4:08]

This video demonstrates how to evaluate expressions when a symbol is given rather than an addition, subtraction, multiplication or division sign. It provides four examples and utilizes variable substitution. Practice problems available....

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 demonstrates how to evaluate an expression with two variables using substitution. [1:46]

A video that demonstrates how to substitute variables in order to evaluate a formula. The formula is given in the example. [1:15]

A video that demonstrates how to use order of operations to evaluate expressions with and without variables. Some expressions contain up to two variables. [14:23]

This video demonstrates how to evaluate expressions when a symbol is given rather than an addition, subtraction, multiplication or division sign.

Introduction and examples of variables, expressions and equations.

This video demonstrates how to solve a word problem using an expression and substituting values for a variable.

This video demonstrates how to evaluate an expression with two variables using substitution.