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Day 13 · Factor out what is commonYear 8 Maths · T1 W3–4 · Day 13 lesson

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Year 8 / Mathematics / 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 · Sources and materials · Daily routes · Worked swaps · 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

Codes: AC9M8A01. Goal: reverse distribution and explain why two forms match. Prepare: expression tile mat.

  1. Launch · 2 min. Write 6x+12. Ask what appears in six equal groups.
  2. Model · 5 min. Six x tiles and twelve unit tiles can be shared into six equal groups of x+2: 6x+12=6(x+2). Expand back. At x=3, both are 30.
  3. Guided · 6 min. 4p+20=4(p+5); expand to verify. At p=2, both equal 28. Show a common numerical factor; do not call 4(p+20) equivalent.
  4. Practice · 6 min. D13-A/B/C choose grouping, narrated expansion or factorisation critique. Each route shows a factor and an inverse expansion.
  5. Exit · 4 min. Complete 3t+15=3(t+__): blank 5. Verify with t=1: 18 on each side.
  6. Note · 2 min. If learner identifies a factor but cannot verify, expand their brackets aloud and compare coefficients.

Later: Day13 extra explores more than one common factor without making greatest-factor fluency a hidden prerequisite.

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