Warm-Up 1
Day 7: Proportional Relationships
Recognize proportional relationships from tables, graphs, and simple situations.
Student Goal
I can decide whether a relationship is proportional.
Why It Matters
Proportional relationships are a major 7th grade idea and help students describe steady rates in real-world situations.
Warm-Up
Warm-Up 2
Which point is the origin?
Warm-Up 3
Which ratio is equivalent to 3:5?
Short Lesson
Standard Focus
NC.7.RP: Ratios and Proportional Relationships
Student-Friendly Standard Goal
I can identify proportional relationships using tables, graphs, and real-world clues.
- A proportional relationship has equivalent ratios and a constant rate.
- In a table, the ratio between the two quantities should stay the same.
- On a graph, a proportional relationship appears as a straight line through the origin.
Guided Examples
Guided Example 1
Check a Table
Does this table show a proportional relationship?
| Hours | 1 | 2 | 3 |
| Dollars | 8 | 16 | 24 |
Step 1
8 / 1, 16 / 2, 24 / 3
What do these ratios equal?
Guided Example 2
Use a Graph Clue
A graph is a straight line, but it crosses the y-axis at 3 instead of the origin. Is it proportional?
Step 1
origin = (0, 0)
What graph clue should you check?
Practice
Problem 1
A table has x-values 1, 2, 3 and y-values 5, 10, 15. Is it proportional?
Problem 2
Which graph clue supports a proportional relationship?
Problem 3
If 2 notebooks cost 6 dollars at a proportional rate, how much does 1 notebook cost?
Problem 4
True or false: A proportional table has equivalent ratios.
Problem 5
Which table is not proportional?
Reflection
How are you feeling about today's skill?
Optional reflection: What clues show that a relationship is proportional?