# Lesson Plan: Rationalizing Denominators Mathematics • 10th Grade

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to rationalize square roots in the denominators of fractions.

#### Objectives

Students will be able to

• simplify a fraction with a square root in the denominator by multiplying both the numerator and the denominator by a square root,
• understand the concept of the conjugate of an expression with square roots and the properties it has,
• simplify an expression with square roots by multiplying both the numerator and the denominator by the conjugate of the denominator,
• solve algebraic problems involving the rationalization of denominators (including division of expressions with square roots).

#### Prerequisites

Students should already be familiar with

• adding, subtracting, and multiplying expressions with square roots,
• properties of addition and multiplication over the real numbers.

#### Exclusions

Students will not cover

• cube roots,
• dividing radical expressions with more than two terms.