In this lesson, students explore a different situation that can be modeled using a polynomial function. They make connections between equivalent expressions for a polynomial function, the function’s graph, and the situation it models before being formally introduced to the term “polynomial” at the end of the lesson. A polynomial function of is a function given by a sum of terms, each of which is a constant times a whole number power of . The word “polynomial” is used to refer both to the function and to the expression defining it.

Students begin by looking at something familiar in a new way, identifying parallel structures between the base-10 number system and polynomials (MP7). They will draw on these parallel structures to better understand polynomial division in later lessons. Students also have an opportunity to practice evaluating polynomials for different inputs. Students then examine a financial context, building a polynomial to model a simple investment account.