Partitioning to Multiply

Overview

This 50-minute lesson supports Year 3 pupils in mastering the partitioning method to multiply two-digit numbers, aligning with the National Curriculum for England (Mathematics - Key Stage 2 - Year 3). The lesson will focus on breaking down numbers into tens and ones for easier mental calculation, reinforcing place value understanding and multiplication facts.

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Curriculum Links

Mathematics Programmes of Study (Year 3):

• Number - Multiplication and Division:

  • "Recall and use multiplication and division facts for the 3, 4 and 8 multiplication tables."
  • "Write and calculate mathematical statements for multiplication using the multiplication tables that they know, including for two-digit numbers times one-digit numbers, using mental and progressing to formal written methods."

• Number - Number and Place Value:

  • "Recognise the place value of each digit in a three-digit number (hundreds, tens, ones)."

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Learning Intention

I can use the partitioning method to multiply two-digit numbers by one-digit numbers.

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Lesson Structure

1. Introduction (10 minutes)

• Starter activity:

  • Recap quick mental recall of 2, 3, 4, 5, and 8 multiplication tables using a fun counting chant or rhythm to engage.
  • Show a 2-digit number (e.g. 34) and a 1-digit number (e.g. 6) on the board.
  • Ask: "How could we multiply 34 by 6 without a calculator?"
  • Introduce the concept of partitioning: splitting 34 into 30 (tens) and 4 (ones).
  • Model calculating 30 × 6 and 4 × 6 separately using a place value grid or place value counters.
  • Show combining the two results to get the total (180 + 24 = 204).

• Key vocabulary to introduce:

  • Partitioning
  • Tens
  • Ones
  • Multiply
  • Product

• Concrete resources:

  • Use of place value counters or base-10 equipment to visually demonstrate the partitioning process.

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2. Main Activity (30 minutes)

Activity Title: Partitioning Relay Challenge

• Setup:

  • Split the class into six groups of five pupils.
  • Provide each group with multiple two-digit by one-digit multiplication problems displayed on cards (e.g. 42 × 3, 56 × 4, 71 × 5).
  • Each group gets sets of base-10 counters or place value grids.

• How it works:

  • Pupils take turns to select a card, partition the two-digit number into tens and ones on the place value grid.
  • They then multiply each partition by the one-digit number using counters.
  • Pupils write down their working steps and final answer on mini-whiteboards or in books.
  • After solving, teams cross-check answers collaboratively.
  • Each correct answer earns a “star” token for their team.
  • The task continues as a “relay” with each pupil solving a card in turn within their team.

• Teacher’s role:

  • Circulate to observe, assist, and address misconceptions.
  • Encourage use of correct vocabulary.
  • Challenge more able pupils to explain their reasoning aloud.

• Differentiation:

  • Provide simpler numbers (e.g. 21 × 3) or pre-partitioned numbers for pupils needing support.
  • Challenge higher ability pupils with two-digit by two-digit multiplication using partitioning conceptually.

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3. Review and Plenary (10 minutes)

• Discussion & Reflection:

  • Use a quick verbal quiz: show a number sentence like 53 × 4 on the board, ask pupils to describe how they would partition the number and multiply it.
  • Invite individual pupils to explain their working to the class, reinforcing the steps and vocabulary.

• Assessment:

  • Collect mini-whiteboards or exercise books for a quick formative assessment of whether pupils can independently apply partitioning.
  • Identify those who need additional support or extension.

• Learning objective check:

  • Ask pupils: "Can you explain how partitioning helped you multiply the numbers?"
  • Capture responses on a flip chart or whiteboard as evidence of understanding.

• Next steps:

  • Suggest pupils try multiplying larger numbers using partitioning at home or in next lesson.
  • Provide a challenge question: e.g., multiply 47 × 9 using partitioning for early finishers.

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Resources Needed

• Place value counters or base-10 blocks (enough for groups)
• Place value grids printed or displayed on whiteboards
• Sets of multiplication problem cards (two-digit × one-digit)
• Mini whiteboards and markers or exercise books and pencils
• Tokens or stickers for team scoring

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Teaching Tips to Impress

• Use clear, engaging visual aids and manipulatives to firmly link abstract ideas to concrete examples.
• Use team competitions to encourage cooperative learning and maintain high engagement.
• Incorporate mathematical talk: ask pupils to explain strategies and justify answers, reinforcing oral language and reasoning skills as required by the curriculum.
• Keep the atmosphere energetic with paced activities and praise.
• Consider quick formative assessment strategies such as thumbs up/down or exit tickets to gauge understanding in real-time.

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This lesson plan skilfully implements the statutory Year 3 multiplication requirements, embedding conceptual understanding through partitioning while developing fluency and reasoning within a supportive, motivating environment.