Math lesson plan · 8th grade (Year 9 in England) · 30 minutes
Identify transformations from coordinate rules
Geometry
CCSS 8.G.A.3England: KS3 Geometry and measuresEngland: GCSE Foundation Geometry and measures
Objective and success criteria
Students will: Identify transformations from coordinate rules.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Reflect and rotate points on the coordinate plane; Translate points and describe translations
Leads to: the next skill in this area.
Materials: Rulers and protractors, Squared or dotted paper, Shape cut-outs, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Reflect and rotate points on the coordinate plane; Translate points and describe translations). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
Hook · 3 min
- Show a photo of a building, a tile pattern or a road sign and ask what shapes and angles students can spot.
- Share the objective: Identify transformations from coordinate rules. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which transformation is described by (x, y) → (x, −y)?
- Step 1: Reflection in the x-axis
- Answer: Reflection in the x-axis
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which transformation is described by (x, y) → (−y, x)? (Reflection in the x-axis / Reflection in the y-axis / Rotation of 90° anticlockwise about the origin / Translation) → Rotation of 90° anticlockwise about the originPrompt: Try it on a point such as (2, 1) and sketch the result.
- After a dilation with scale factor 1/2, is the image congruent to the original (same size and shape)? (Yes, congruent / No, only similar) → No, only similarPrompt: Translations, reflections and rotations keep lengths and angles.
You do: independent practice · 7 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Which transformation is described by (x, y) → (x, −y)? (Rotation of 90° anticlockwise about the origin / Translation / Reflection in the x-axis / Reflection in the y-axis) → Reflection in the x-axisPrompt: Try it on a point such as (2, 1) and sketch the result.
- After a reflection, is the image congruent to the original (same size and shape)? (Yes, congruent / No, only similar) → Yes, congruentPrompt: Translations, reflections and rotations keep lengths and angles.
Watch out for
- Thinking a square turned on its corner is no longer a square.
- Reading the wrong scale on a protractor.
Support and stretch
Support
- Review first: Reflect and rotate points on the coordinate plane.
- Use concrete materials: rulers and protractors.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-8.
Free lesson plan from eurekami.com/lesson-plan-builder