# Variables & expressions introduction

Contents

Learn what variables are and practice using them in expressions. The major concepts covered in these tutorials are substitution, the distributive property, and combining like terms.

Wait, why are we using letters in math? How can an 'x' represent a number? What number is it? This tutorial is great if you're just beginning to delve into the world of variables and expressions.

Learn how to substitute (or "plug in") values for variables and evaluate algebraic expressions.

Explore how the value of an algebraic expression changes as the value of its variable changes.

Learn how to plug in values to evaluate real-world expressions.

Learn the basics of writing expressions with variables.

Learn how to write algebraic expressions (expressions with variables) to model real-world situations.