A fictional learner says: “The output jumps by 4, then 6, so the rate changes.” In a supplied linear model, points (1, 7), (3, 11) and (6, 17) have unequal input intervals. The changes are 4 ÷ 2 = 2 and 6 ÷ 3 = 2 output units per input unit. Compare rates, not raw jumps across different intervals.
Your new practice
A supplied linear cord model for 0 to 8 minutes gives these totals. Calculate the rate over each displayed interval. Write one sentence about why the output jumps differ, and check the claim “24 ÷ 5 gives the change rate.”
| Time (minutes) | Total cord (meters) |
|---|---|
| 1 | 8 |
| 5 | 24 |
| 8 | 36 |
Your two rates, units and response to the claim
For a next task, keep the two differences in the same order. If quantity direction is unclear, first label input, output and the unit sought.