Ratios and Proportions
Grade 7 · Math · Proportional Relationships · Oklahoma, USA
Lesson Summary
Learn what ratios and proportions are and how to tell whether two ratios form a proportion.
Explanation
A ratio compares two quantities, like 3 apples to 5 oranges, which you can write as 3:5 or 3/5. A proportion is an equation that says two ratios are equal, such as 3/5 = 6/10. You can check whether two ratios form a proportion by cross-multiplying: if the cross products are equal, the ratios are proportional. Proportions show up everywhere, from recipes to maps to speed calculations.
Practice Questions
Q1: Do the ratios 4/6 and 10/15 form a proportion? Explain how you know.
Answer: Yes. Cross-multiply: 4 × 15 = 60 and 6 × 10 = 60. Because the cross products are equal, the ratios form a proportion.
Q2: Write the ratio of 12 wins to 8 losses in simplest form.
Answer: 12/8 simplifies to 3/2, or 3:2.
Q3: A store sells 5 notebooks for $8. How much would 15 notebooks cost at the same rate?
Answer: Set up the proportion 5/8 = 15/x. Cross-multiply: 5x = 120, so x = 24. Fifteen notebooks cost $24.
People Also Ask
What is Ratios and Proportions in Grade 7 Math?+
Ratios and Proportions is a lesson in the Proportional Relationships chapter of Grade 7 Math. It is part of the Oklahoma, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Ratios and Proportions?+
Ratios and Proportions is taught in Grade 7 as part of the Math curriculum in Oklahoma, USA.
How can I help my child with Proportional Relationships in Math?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Proportional Relationships topics.