CCSS.Math.Content.7.RP.A.2a
The standard
Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
Common Core State Standards for Mathematics
What this standard means
Students need to decide if two quantities grow at a constant rate together. They should check a table by comparing ratios, simplifying fractions, or finding the unit rate for each pair. They should also graph ordered pairs and look for a straight pattern that starts at zero.
Mastery looks like students can say yes or no and justify it with numbers, a graph, or both. Common trouble spots are mistaking any straight line for a proportional relationship, ignoring whether it passes through zero, and comparing differences instead of ratios.
Ways to teach it
- Hands-on activity: Give pairs measuring cups and colored water, then have them test which recipe tables keep the same juice-to-water ratio.
- Writing prompt: Show two tables and ask, Which one is proportional, and what evidence proves it?
- Quick assessment: Use three mini tables and one graph, then have students label each proportional or not with one reason.
- Real-world connection: Compare two store price lists for apples and decide whether each store uses a constant price per pound.
Plan a lesson for CCSS.Math.Content.7.RP.A.2a
Generate a complete lesson plan aligned to this standard, with objectives, activities, and materials. Free, no account needed.
Related standards
- CCSS.Math.Content.7.RP.A.2
Recognize and represent proportional relationships between quantities.
- CCSS.Math.Content.8.EE.B.5
Graph proportional relationships, interpreting the unit rate as the slope of the graph. Compare two different proportional relationships represented in differen...
- CCSS.Math.Content.7.RP.A.2b
Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
- CCSS.Math.Content.7.RP.A.2c
Represent proportional relationships by equations.