Clever Kitchen Maths

Curriculum Context

Learning Area: Mathematics and Statistics
Strand: Number and Algebra
Achievement Objectives:

• Level 3 (Year 5): Investigate and describe patterns in numbers, including multiplication and division, and use these to solve problems involving ratios.
• Level 4 (Year 7): Use proportional reasoning to solve number problems, including those involving ratios.

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Lesson Duration

Total Time: 17 minutes
Class Size: 25 students
Focus: I can simplify a ratio; I can use a known ratio to scale quantities.
Differentiated Groups:

• Group Rimu (Year 5)
• Group Kauri (Year 7)

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Learning Intention

✔ I can simplify a ratio.
✔ I can use a known ratio to scale quantities.

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Success Criteria

By the end of the lesson, students will be able to:
✅ Determine when a ratio can be simplified.
✅ Apply multiplication or division to scale a ratio up or down.
✅ Solve a context-based problem using ratio reasoning.

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Resources Needed

• Pre-prepared laminated “Smoothie Recipe Cards” (different quantities of ingredients with ratios to match)
• Whiteboard and markers
• Colour-coded fraction tiles or small measuring cups for hands-on illustration
• Mini whiteboards and pens for groups
• Printed “Quick Ratio Challenge” slips for exit activity

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Lesson Breakdown

⏱️ 0-2 mins – Engage: Whip-Up Smoothies

Purpose: Hook their interest within a context that feels real and local.

🗣 Teacher says:

“Today, we’re opening a smoothie shop! You’ll help us make the word’s yummiest kai—but we need your maths smarts. We have secret family recipes from Southland to Northland, and your job is to help us serve the perfect ratio.”

Write on board: "Mango : Banana = 2 : 3"
Ask: “What does that mean?” Brief class discussion.

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⏱️ 2–6 mins – Mini-Workshop: Let's Ratio!

Group Rimu (Year 5)

• Learners work with simplified fruit visuals and build actual ratio sets using fraction tiles—e.g., 2 yellow tiles for mango vs 3 white tiles for banana.
• Walk students through simplifying:

  If you have 4 mangoes and 6 bananas, what’s the simplest form? What number can divide both 4 and 6?

Group Kauri (Year 7)

• Learners are presented with a more complex task:

  "If I need to serve 60 smoothies using the 2:3 mango to banana ratio, how many pieces of each fruit do I need?"

• Support them to multiply both parts of the ratio.

🧠 Prompt proportional thinking with question cards:

• "If the ratio doubles, what happens to the total?"
• "How do you keep ratios equivalent even as numbers grow?"

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⏱️ 6–13 mins – Hands-On Challenge: Smoothie Mix-Off

Split learners into five even groups (mix Y5 and Y7 where possible with Y7 giving leadership roles). Each group receives a "Smoothie Recipe Card" like:

“Blueberry Burst – Ratio: 3 : 2 : 1 (blueberry : milk : banana)”
Scale it up to serve:
a) 1 person
b) 3 people
c) 6 people

📝 Each group writes their scaled recipes on mini whiteboards.
🎯 Teacher circulates, scaffolding students’ thinking by asking guiding questions:

• “Which operation helped you move from 1 to 3 servings?”
• “Did you keep the ratio parts balanced?”

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⏱️ 13–15 mins – Wrap-Up Wow: Ratio Relay

Pull the class back together.
Quick-fire quiz: you say a ratio; students race to show the simplified form or scaled version on their mini-whiteboard.

Examples:

• Simplify: “9:6”
• Scale up: “2:5 for 10 smoothies?”

Class checks answers together by holding up whiteboards.

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⏱️ 15–17 mins – Exit Tickets: Quick Ratio Challenge

Hand each student a slip of paper with a 1-question challenge differentiated by group.
Group Rimu: “Simplify 6:9”
Group Kauri: “If the ratio of water to concentrate is 2:5, how much water is needed for 15L of concentrate?”

🗂 Collect these as they leave for formative assessment direction tomorrow.

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Assessment Opportunities

Observation Point	What to Look For
Group task	Are students accurately scaling ratios together? Are Group Kauri using multiplication effectively?
Mini-whiteboard review	Are students confidently simplifying? Can they reverse engineer a ratio?
Exit ticket	Do responses show level-appropriate understanding? Who needs follow-up support?

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Differentiation Strategies

🎯 Group Rimu:

• Concrete manipulatives
• Simplification focus only
• Smaller numbers
• Guided questions

🔍 Group Kauri:

• Larger numbers
• Hypothetical scaling contexts
• Opportunities to explain reasoning in pairs
• Encourage independent problem solving

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Extension Ideas

• Students invent their own smoothie recipes with unique fruit ratios and challenge another classmate to scale it up.
• Integrate with literacy — write a persuasive menu description to "sell" their smoothie using mathematical language (e.g. “perfectly balanced at a 3:2:1 ratio for maximum flavour!”).

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Teacher Reflection Prompts

• What strategies helped students grasp proportionality?
• Did mixed-ability grouping enhance collaboration or present challenges?
• Who may benefit from targeted guided teaching next lesson?

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🚀 This lesson turns ratios into something deliciously tangible—a playful yet purposeful bridge into more abstract proportional reasoning.