This document introduces algebraic expressions and polynomials. It defines algebraic expressions as involving variables, constants, or both. Polynomials are defined as the sum of polynomial terms, where a term is a constant or the product of a constant and variables raised to positive integer powers. The document provides examples of evaluating algebraic expressions and describes relationship machines to represent expressions visually. Key polynomial terminology is introduced, such as monomial, binomial, trinomial, coefficients, constant terms, and degree. Examples are given to classify expressions and polynomials.