Math lesson plan · 1st grade (Year 2 in England) · 30 minutes
Which shape does not belong, and why?
Geometry
CCSS 1.G.A.1England: Y1 GeometryEngland: Y2 Geometry
Objective and success criteria
Students will: Which shape does not belong, and why?.
- 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: What makes a shape that shape?
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 (What makes a shape that shape?). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which is always true about every hexagon? (It is blue / It has 6 straight sides / It points upwards / It is big) → It has 6 straight sidesPrompt: Colour, size and which way it faces can change.
- Which of these is a hexagon? (A shape with 6 straight sides that do not join up / A shape with 6 curved sides / A shape with 7 straight sides / A shape with 6 straight sides that meet at 6 corners) → A shape with 6 straight sides that meet at 6 cornersPrompt: A hexagon is a closed shape.
- Which is always true about every triangle? (It is blue / It is big / It points upwards / It has 3 straight sides) → It has 3 straight sidesPrompt: Colour, size and which way it faces can change.
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: Which shape does not belong, and why?. 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 shape does not belong: square, triangle, rectangle?
- Step 1: The triangle: it has 3 sides, the others have 4.
- Answer: triangle
- 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 shape does not belong: rectangle, triangle, square? (rectangle / triangle / square) → trianglePrompt: Count the sides of each shape.
- Which shape does not belong: circle, pentagon, hexagon? (circle / pentagon / hexagon) → circlePrompt: Count the sides of each shape.
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 shape does not belong: hexagon, circle, pentagon? (hexagon / circle / pentagon) → circlePrompt: Count the sides of each shape.
- Which shape does not belong: circle, triangle, square? (circle / triangle / square) → circlePrompt: Count the sides of each shape.
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: What makes a shape that shape?.
- 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-1.
Free lesson plan from eurekami.com/lesson-plan-builder