### Unit 7: Operations with Monomials

Starting with this unit, you will work with expressions that consist mostly of letters (variables) and do not seem to have very much to do with numbers. You will see how the rules governing operations with these expressions arise from the properties of operations with numbers, particularly distributive property and order of operations. This unit focuses on expressions called monomials. These are expressions that contain only one term (recall from Unit 1 what "term" means). The fact that monomial contains the Greek word mono, which means one, can help you remember this definition. For example, expression *ab* is a monomial, but *a + b* is not, because it contains two terms.

**Completing this unit should take you approximately 7 hours.**