Lesson 1: Understanding Rational Expressions

• What is a rational expression?
• Why can't the denominator be zero?
• What restrictions do we need?
• How are rational expressions like fractions?

Rational expression, numerator, denominator, restriction, undefined, variable

CCSS.MATH.9.A.SSE.A.1

Description: Rational expressions are introduced as fractions with polynomials in the numerator and denominator. Students learn that the denominator cannot be zero and identify restrictions (values that make the denominator zero). Purpose: To establish foundational understanding of rational expressions and why restrictions matter. DOK Level: 1-2 (Recall and Understanding)

• Connection to fractions: Use familiar fraction concepts
• For struggling learners: Focus on simple rational expressions with linear polynomials
• For advanced learners: Include more complex polynomials
• Anchor chart: Display restrictions and undefined values

• Observation: Can students identify rational expressions?

• Restriction task: Find values that make the denominator zero

• Worksheet: Identify rational expressions and their restrictions

• Exit ticket: Explain why denominators can't be zero

• Rational expression examples

• Restriction identification guides

• Practice worksheets

• Anchor chart for restrictions

• Resource: Khan Academy "Rational Expressions Introduction" (adapted)