Exploring Multiplication Magic

Curriculum Links

Australian Curriculum: Mathematics
Year Level: Year 4
Strand: Number and Algebra
Sub-strand: Number and Place Value
Content Description: Solve problems involving multiplication of large numbers by one- or two-digit numbers using a range of strategies (ACMNA081).

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Learning Intention

We are learning to use different strategies to solve multiplication problems up to two-digit numbers, so that we can build a deeper understanding of times tables and number patterns.

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Success Criteria

• I can solve basic multiplication problems confidently.
• I can use strategies like arrays and partitioning to solve more complex multiplication problems.
• I can explain my thinking when solving a multiplication problem.

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Materials Needed

• Mini whiteboards and markers (1 per student for quick responses).
• 20 counters or small objects per student.
• Multiplication flashcards (pre-prepared with one- or two-digit multiplication challenges).
• Grid paper (optional).
• A printed “token board” with four reward spaces per team (see below for explanation).

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Structure of Lesson

1. Introduction (5 minutes) – Context Setting

Activity: Multiplication in the Real World
Ask students:

• “Why do we learn multiplication? When might we need it in real life?”
  Encourage discussion, with examples such as splitting groups in team sports, planning a party, or working out costs when shopping.

Quick Warm-Up:

• Using mini whiteboards, play "Fast Facts"—call out quick multiplication problems from the 1–10 times tables (e.g., 3x4, 6x7). Students write their answers and hold them up.

Transition smoothly into today’s focus: “Today, we’ll learn some multiplication tricks to solve harder problems quickly and easily—like how to multiply numbers like 25 x 12!”

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2. Activity 1: Hands-On Practice (10 minutes) – Playing with Counters

Teaching Focus:
Use visual aids to demonstrate multiplication as grouping. For example:

• Show 3x4 using counters to arrange 3 rows of 4 counters each and discuss the total.
• Draw parallels between array arrangements (rows and columns) and real-world objects like blocks or seating arrangements.

Student Task:

• Split the class into pairs. Provide each pair with 20 counters.
• Assign them simple problems to model: e.g., "Show me 2x5, now 4x3." Discuss answers as a group.
• Progress to two-digit numbers (e.g., model problems like 12x2 on grid paper using repeated addition or breaking the number into smaller parts).

Success Tip for Differentiation:

• Confident students can create their own multiplication problems using counters for a partner to solve, while students needing support can stick to guided problems.

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3. Activity 2: Brainstorming Strategies (10 minutes) – Creative Thinking

Activity: Strategies Shuffle Game
Divide the class into four groups and assign one strategy per group.

1. Skip Counting (e.g., for 6x8, count by 6s: 6, 12, 18, etc.).
2. Doubling and Halving (e.g., for 14x6, think of it as 7x12).
3. Arrays (drawing rows/columns to represent the problem).
4. Partitioning (breaking numbers into parts, e.g., 23x4 → (20x4)+(3x4)).

Each team has to show how their strategy solves the problem 15x6. Once done, they explain their thinking to the class and compare strategies.

Bonus Engagement: Introduce a "token reward system." Each group earns a token every time they show great teamwork or innovative thinking.

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4. Plenary (5 minutes) – Reflection and Challenge

Ask reflective questions:

• “Which strategies did you find easiest or most useful? Why?”
• “What would you tell a younger student about how to solve 25x12?”

Challenge Question (for fast finishers or everyone on mini whiteboards):
“How might you solve 36x8? Write and explain your thinking!”

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Extension for Advanced Learners

For capable or fast-finishing students, introduce the idea of estimating multiplication problems to check their answers (e.g., solving 49x9 by estimating 50x10).

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Assessment Opportunities

• Observe during the counter activity: Are students arranging correct groups and counting totals accurately?
• During the Strategies Shuffle, listen to how students explain their thinking—can they communicate their strategy clearly?
• Use the reflective response or whiteboard challenge to assess individual understanding.

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Wrap-Up and Connection to Life

“Think of how often people use multiplication every day. Your parents, shopkeepers, sport coaches all use it! Can you spot an example of multiplication at work this week and share it in class?”