Sorting Shape Properties

Overview

Lesson 3 of 15 in Shapes, Space and Reasoning. Students classify 2D shapes and 3D objects by observable properties, then justify and test sorting rules using hoops, cards and a sorting mat. The lesson is designed for five Year 4–6 learners working collaboratively, with visual instructions and generous wait time.

Learning intentions

• WALT classify 2D shapes and 3D objects according to their properties.
• WALT identify and compare properties such as sides, faces, edges, vertices, angles and curved surfaces.
• WALT explain and test a sorting rule.
• WALT use mathematical language and visual reasoning to communicate our thinking.

Success criteria

• I can sort shapes or objects consistently using one or more properties.
• I can state the rule I used for a group.
• I can explain why an object belongs, or does not belong, in a group.
• I can check whether another person’s sorting rule works for every card.

Curriculum links

• Geometry: identify, describe, compare and classify 2D shapes and 3D objects using their properties.
• Mathematical reasoning: explain, justify and test strategies and conclusions.
• Mathematical communication: use appropriate language, diagrams and representations to share thinking.
• Key competencies: thinking; using language, symbols and texts; relating to others.

Lesson structure (60 minutes)

1. 0–7 minutes – Notice and wonder hook Display a mixed collection of shape and object images. Open with the hook and lesson overview slides and ask: “What could we use to sort these? Could one object belong in more than one group?” Give silent thinking time, then invite each learner to point to or describe one property they notice. Record vocabulary such as side, face, edge, vertex, angle, curved and straight.

2. 7–15 minutes – Model a sorting rule Demonstrate sorting four or five cards into two hoops using one clear rule, such as “has at least one curved edge” or “has four vertices”. Think aloud while placing each card. Ask learners to show thumbs up, thumbs down or unsure before revealing where a card belongs. Use the modelling and visual reasoning slides to show the rule, examples and a “Does it fit?” routine. Emphasise that the rule must work consistently, not just for one card.

3. 15–30 minutes – Guided sorting in pairs and trio Give learners a mixed set of 2D shape and 3D object cards, two hoops and a sorting mat. The cards may include familiar shapes and objects such as triangles, rectangles, circles, cubes, cuboids, cones, cylinders and spheres. For initial support, provide one property prompt: “Sort by curved/straight surfaces”, “Sort by number of vertices” or “Sort by number of sides.” Learners place cards, then explain the rule to a partner before changing or checking the group. Use the 2D shape property cards as a visual reference for learners who need named properties and examples.

4. 30–42 minutes – Record and justify Distribute the shape sorting recording sheet. Learners draw or name the rule, record at least three cards in each group, and explain one card that was difficult to place. Circulate and ask: “What is your rule?”, “Does it work for every card?”, and “What evidence can you see?” Accept oral, signed, pointed or drawn explanations. The teaching assistant can record learner explanations where writing is a barrier.

5. 42–53 minutes – Challenge: sort another way Each learner creates a new sorting rule, preferably using two properties, for example “has four sides and at least one right angle” or “has a curved surface and no vertices”. They sort selected cards and ask another learner to work out the rule. Extension learners create a rule with more than one possible answer, such as a group that could be described by either “has four sides” or “has at least two right angles”. Discuss how different rules can produce the same group.

6. 53–60 minutes – Share, check and reflect Use the discussion and plenary slides to display two sorting examples, including one with a misplaced card. Learners silently decide whether the sorting is consistent, then explain their reasoning using the sentence frame: “I think ___ belongs because ___.” Finish with each learner naming one property they can use to sort shapes and one question they still have.

Resources

• the shape sorting teaching deck
• the shape sorting recording sheet
• the 2D shape property cards
• Teacher-made 3D object cards or photographs
• Two hoops or large loops of string
• Digital or physical sorting mat
• Real 3D objects: cube, cuboid, cone, cylinder and sphere
• Whiteboard and markers
• Colour-coded property prompt cards
• Visual timer

Assessment

• Observe whether learners classify consistently and identify the property used.
• Listen for accurate use of terms such as side, face, edge, vertex, curved and straight.
• Check the worksheet for a clear rule, correctly placed examples and a reasoned explanation.
• Use the final reflection to identify learners who need further work distinguishing 2D shapes from 3D objects or describing properties precisely.

Differentiation

• Support learners by beginning with one property, using only familiar shapes, providing colour-coded prompts and modelling one card at a time.
• Offer real objects, photographs, enlarged cards and tactile handling before expecting written explanations.
• Provide sentence frames, gesture/sign support, labelled diagrams and extended wait time; keep all instructions and rules visible rather than relying on spoken directions.
• For deaf learners, face the class when speaking, maintain clear visual turn-taking and use a visual reasoning routine: look, think, place, explain, check.
• Extend advanced learners by requiring two-property rules, identifying overlapping groups or designing a rule with more than one valid description.