Parts and Wholes

Overview

In this interactive session, Reception children will explore the foundational concepts of parts and wholes using tangible counters. Through partner play and guided discussion, pupils will develop early number sense by recognising how smaller groups form a whole. This hands-on, exploratory approach is designed to activate curiosity and mathematical language development, fully aligned to the Northern Ireland Curriculum’s Early Mathematics Area of Learning.

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Curriculum Links

Northern Ireland Curriculum (Foundation Stage) – Mathematics Area of Learning:

• Thinking and Problem Solving: Numbers and Measures (MAT 1-10)

  • Develop an understanding of number through practical activities.
  • Begin to recognise how numbers can be split into smaller parts (partitioning).
  • Use mathematical language to describe quantities and relationships.

• Language and Literacy: Oral Language (LOR 1-1)

  • Participate in discussions, sharing ideas clearly.

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Learning Intentions

By the end of this lesson children will:

• Understand that a set number of counters can be split into smaller groups (parts).
• Recognise and name the whole and its parts.
• Use appropriate vocabulary such as “whole,” “part,” “group,” “more,” and “less.”
• Work cooperatively with a partner to explore different combinations of parts making the same whole.

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Success Criteria

Pupils will be able to:

• Create sets of counters representing a whole number and divide them into smaller parts.
• Explain in simple terms their thinking about the parts and the whole.
• Listen to and describe other pairs’ findings using mathematical vocabulary.

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Resources

• Counters (2 colours, approx. 10 per pair)
• Small trays or mats (one per pair)
• Visual aids: Illustrated poster showing “whole” and “parts” concepts
• Whiteboard and markers
• Name labels for pairs (to encourage ownership and confidence in sharing)

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Lesson Outline (30 minutes)

1. Introduction (5 minutes)

• Engage pupils with a story: “Imagine you have 5 apples in one basket. How can we share these apples into smaller groups?”
• Use the illustrated poster to visually introduce the terms “whole” and “part.”
• Briefly explain that today they will explore how a number can be made of smaller groups.
• Ask a few children to demonstrate with counters what they think “whole” and “part” mean.

2. Main Activity: Partner Work Exploring Counters (15 minutes)

• Grouping: Children form pairs and receive 10 counters and a tray each.
• Task: “Make one whole group of counters, then split the group into two smaller parts in different ways. How many can you put in one part? How many in the other?”
• Encourage pupils to discuss what they are doing with their partner, prompting with questions like:
  • “How many counters are in the whole group?”
  • “Can you make a different part and still keep the same whole?”
  • “Which part has more or less?”
• Teacher circulates, supporting language use, modelling correct vocabulary, and encouraging full sentence responses (“I have 3 counters in this part and 7 in the other. The whole is 10.”).

3. Sharing and Reflecting (8 minutes)

• Invite 2–3 pairs to share their findings with the class beside the whiteboard.
• Use the whiteboard to illustrate their groups visually, reinforcing the parts-whole relationship.
• Encourage other children to ask questions or add ideas.
• Highlight different ways of making the same whole (e.g., 4 + 6, 5 + 5, 2 + 8).
• Praise use of mathematical vocabulary and turn-taking.

4. Plenary – Group Recap and Vocabulary Focus (2 minutes)

• Recap key vocabulary as a whole class, using the poster for visual support.
• Ask children to say one thing they learned about parts and wholes.

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Assessment Opportunities

• Formative observation: Monitor partner conversations, noting use of vocabulary and confidence in describing parts and wholes.
• Teacher questioning: Use scaffolded questions to gauge understanding during activities.
• Pair sharing: Informally assess each pair’s grasp through their verbal explanations shared in the plenary.

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Differentiation and Inclusion

• Provide pairs with varied numbers of counters to match ability (e.g., 5 instead of 10) for children needing extra support.
• Challenge more confident learners to explore splitting wholes into three parts or use reasoning questions (“Can you make two parts that are the same?”).
• Use visual and tactile resources to support children with additional sensory needs.
• Model language clearly and offer sentence starters to support verbal explanations.

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Next Steps

Lesson 2 and 3 in this unit will gradually introduce written recording of parts and wholes and connect this understanding to simple addition, deepening their conceptual grasp within a contextual framework.

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By connecting hands-on exploration, purposeful dialogue and visual representation, this lesson actively addresses the Northern Ireland Curriculum’s focus on experiential learning and communication skills, laying a strong mathematical foundation for Reception children.