Math Lesson Plan · Grades 6–9
Proportions Lesson
Teach students to solve proportions using cross-multiplication. The lesson introduces the concept of equal ratios and shows how to set up and solve a proportion for the unknown value. Includes 20 practice problems and answer key.
Subject
Math
Grades
Grades 6–9
Skill Focus
Proportions, ratios, cross-multiplication, algebra, math
Lesson Length
30–45 minutes
Lesson Overview
Setting Up and Solving Proportions
A proportion is an equation stating that two ratios are equal: a/b = c/d. To solve for an unknown, use cross-multiplication: multiply the numerator of each fraction by the denominator of the other, then solve the resulting equation. The lesson introduces this strategy with clear worked examples.
The six-page lesson covers proportion setup and cross-multiplication with a range of contexts including rates and scale. Students complete 20 practice problems and check their work using the answer key on page 6.
How to Use This Lesson
1. Introduce proportions and equal ratios (pages 1–2). Show how to identify a proportion.
2. Demonstrate cross-multiplication with worked examples (pages 3–4). Practice setting up and solving proportions.
3. Assign the 20 practice problems (page 5) independently. Review answers using the key on page 6.
Printable Resource
A classroom-ready PDF with everything in one printable resource.
Full Member Resource · Printable PDF · 6 pages
Proportions Lesson
Six-page printable: proportions concept, cross-multiplication strategy, 20 practice problems, and answer key. Grades 6–9.