Stretch: Missing Values and Points on a Line
I can fill missing values in a ratio table and recognize that the points lie on a straight line through the origin.
🧠 The Challenge
equivalent ratioratio tablecoordinate planeline through origin
Equivalent ratios plotted as (x, y) points always fall on a straight line through the origin. The unit rate is the steepness.
👀 Worked Example
| x (cups mix) | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| y (cups water) | 3 | 6 | 9 | 12 |
Points (1,3), (2,6), (3,9)… all lie on one line through (0,0). The rate is 3 water per 1 mix.
✏️ Your Turn
0 of 3 checks complete
1. In the table above, what is y when x = 5?
2. The points from an equivalent-ratio table always lie on…
3. Ratio 2:5. Which point belongs on its graph?
💬 Explain Your Thinking
Explain why equivalent ratios form a straight line:
"Each point multiplies both numbers by the same factor, so the points blank through (0, 0)."