Modeling with a Linear Function Worksheets

Sample problems

1. A plant is 12 cm after 2 weeks and 24 cm after 5 weeks. Find the rate of growth.
2. Same plant. How tall was it at week 0?
3. Write the plant's model and check it on both readings.
4. Interpret both numbers in your model, in words, with units.

Common mistakes to watch for

• Answered £8 — the difference rather than the rate. A difference and a rate are different quantities, and only one of them is per mile.
• Gave £5 with no interpretation, or gave £11. The standard names interpretation explicitly, so a bare number is half an answer.
• Checked only one reading. Same trap as checking a system in one equation — the reading you used to build the model cannot test it.

The answer key explains each one, so you can tell what a wrong answer means.