SubjectNest resource library

Development draft · local review needed

Day 4 — The midpoint averages each coordinateYear 9 Maths · T1 W1–2 · Day 4 lesson

Prepare this lesson

Year 9 / Mathematics / Term 1 / Weeks 01 02

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

Open for this lesson: Pack guide.

Download full sequence

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.

Goal/materials: locate halfway point even with negative coordinates; grid, Cards 5–6.

  1. Notice, 3: On a line, what is halfway between -6 and +4? Key: -1. Check equal distance 5 each way.
  2. Model, 5: Card 5 A(-6,2), B(4,8). “Average x values: (-6+4)/2=-1. Average y: (2+8)/2=5. Midpoint (-1,5).” Plot and check equal horizontal/vertical moves.
  3. Together, 8: Card 6 (-3,-4),(5,2) ⇒ M(1,-1). Swap point order to show midpoint invariant. Check x displacements 4/4, y 3/3.
  4. Try, 6: Fresh design segment (-5,-1)→(3,7). Key: M(-1,3). Learner may state/plot and justify equal displacement.
  5. Check, 3: “Midpoint of (1,5) and (7,-1)?” Key: (4,2). If coordinate pairs are cross-averaged, colour/tactile-code x with x and y with y, then try a new pair.

Source: https://neuroforge.io/subjectnest/library/resources/year-9/mathematics/term-1/weeks-01-02/day-04 · Original material © NeuroForgeIO Pty Ltd 2026 · CC BY 4.0: https://creativecommons.org/licenses/by/4.0/ · Credit the source and note changes. External sources keep their own terms.