Grade 9 · Number
Proportional Reasoning — Percents, Rates, and Scale
Proportional reasoning deepens in Grade 9. Students tackle multi-step percent problems (a 15% salary increase followed by a 10% decrease), scale factor problems (similar triangles, map distances), and financial applications (simple interest, exchange rates). Each context strengthens the underlying multiplicative relationship.
LESSON VIDEO
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Lesson video
A short walkthrough to play in class or assign for flipped/at-home viewing.
WHAT STUDENTS WILL LEARN
✓Solve multi-step percent problems: percent change, original value, final value
✓Solve problems involving rates, unit rates, and unit conversion
✓Apply scale factors to diagrams, maps, and similar figures
✓Use proportional reasoning to solve real-world financial problems