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Day 17 · Explore a factor, not just a fit · AC9M9A01 · AC9S9I04…Year 9 Inquiry · T1 W3–4 · Day 17 lesson

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Year 9 / Integrated / Term 1 / Weeks 03 04

Part of the full two-week lesson sequence. Check the pack guide and taught point before teaching.

Open for this lesson: Pack guide · Fresh learner checks · Aids and text routes.

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Teacher copy: This page may include teaching prompts or answer keys. Answer keys in this public library can be viewed by anyone. Give learners a clean prompt, use checks as formative evidence, and change a case locally when prior access matters.

Learner prompts

Question: Can a different constant factor match the fictional data better without proving a mechanism? Kit: offline model explorer or model table. 35 = 3 + 7 + 12 + 8 + 5.

  1. 0–3: Recall P(n)=160×r^n, with 0<r≤1; if r=0.5, it is the poster's half-model. This extension complements the mathematics exponent-law lessons without reusing their practice values.
  2. 3–10: Teacher runs or traces r=0.50 and r=0.55. The explorer displays predicted rows and mean absolute gap against invented B. Define the gap as an arithmetic comparison, not an uncertainty estimate or proof of cause.
  3. 10–22: Learners run two candidate factors offline or fill a paper table. Compare which fits these five values better, then name at least two reasons fit might not transfer (method, calibration, other paper). A model can match data while describing the wrong mechanism.
  4. 22–30: Explain r^(a+b)=r^a r^b for repeated identical factors and why r=0 cannot be used with negative exponents. Routes: local keyboard or paired navigator with recorded action; tactile repeated-factor cards and teacher-read output; written calculator table with exact-word explanation.
  5. 30–35: “If 0.55 gives a smaller gap, does it prove all paper passes 55% each layer?” Key: no. Response move: mark the model as a fitted conditional description and add a new test requirement.

Another domain: Fit a fictional stage-filter card set, keeping data labelled invented. Home: compare two exponent expressions on paper; no software needed.