Doubles and Halves

Lesson Overview

Year Group: Year 1
Duration: 60 minutes
Curriculum Area: Mathematics
Curriculum Reference: NZ Maths & Statistics, Level 1 (Number Strand)
Learning Outcome: By the end of the lesson, students will explore the concepts of doubling and halving up to 20 using hands-on activities, understand that doubling is "adding the same number" and halving is "sharing equally," and apply basic doubling and halving facts in real-world scenarios.

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Lesson Plan: Doubles and Halves Exploration

Materials and Resources

• Counters (at least 20 per child)
• Base-ten blocks
• A large number mat (1-20)
• Small whiteboards and markers (1 per student)
• Themed printable worksheets (e.g., Buzzy Bees halves & doubles activity, or sheep on a farm counting sets)
• A basket of toy fruit or similar manipulatives for role play (optional)

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Lesson Structure

1. Welcome and Introduction (10 minutes)

Objective: Set the scene and introduce students to the idea of doubles and halves in a fun, relatable way.

1. Hook:
   Begin the lesson by sitting in a circle on the mat. Say to the class:

   “Today, we are going on a maths adventure! We’re going to learn how to double things like magicians and how to halve things like we’re sharing cupcakes with our friends!”

2. Connected Questioning:
   Ask simple questions to initiate prior knowledge:

   • “Who knows what it means to double something?”
   • “If I had 2 apples and doubled them, how many would I have?”
   • “Who’s shared something with their sibling? What does halving mean?”

3. Demonstration using Objects:
   Use 4 counters and say:

   • “Let’s try doubling! If we have 4 counters and add the same amount again, how many do we have altogether?” (Show physical addition).
   • Reverse it for halving: “Let’s now equally share these 8 counters into two halves. How many in each group?”

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2. Guided Practice (15 minutes)

Objective: Use manipulatives to visualise and practise doubling and halving together.

1. Distribute counters and ensure each child has 20.

   • Activity 1 – Doubling Detectives:

     • Introduce doubling through play.
       Say: “We are doubles detectives solving maths puzzles! I will give you a number like 3, and we’ll double it together by making two equal groups of 3 counters.”
       Call out numbers 1 to 10, and let them build two groups with counters. Then count the total amount out loud as a class.

   • Activity 2 – Halves Helpers:

     • Say: “Now we are halves helpers! Let’s imagine we have these counters, and we’re going to share them into two groups so both are the same size.” Call out even numbers, e.g., 6, 8, 10, 12, and let students share their counters into two equal piles to work out the answer.

   • Walk around the room to model and help, ensuring students get the physical practice of grouping and sharing.

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3. Group Activity: Fun with Base-Ten Blocks (15 minutes)

Objective: Collaboratively explore doubles and halves further with a game-like approach.

1. Break the class into 3 groups of 4-5 students.

2. Activity Setup:

   • Place base-ten blocks at each station along with a number mat (1–20).

   • Doubles Station: Students pick a number card from a pile (1–10), place it on the mat, and use blocks to build exactly double that number. They write each doubled amount on their whiteboards.

   • Halves Station: Students choose even-numbered cards (2–20), build that number with blocks, and then split it into two equal groups. They mark their results on the whiteboard.

   • Mixed Station: Cards may call for either “Double” or “Half,” and students use blocks to create their answer.

   Rotate groups after 5 minutes.

3. Teachers or helpers supervise to ensure students remain engaged and offer hints as needed.

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4. Reflection and Application (10 minutes)

Objective: Conclude by applying learning to a real-world context and allowing students to reflect.

1. Reflection Circle:
   Gather the students back on the mat and recap.

   • “What did we learn about doubling and halving today?”
   • “Can you share one example of when you might use doubling (e.g., in cooking, sharing snacks)?”

2. Real-Life Role Play:
   Use toys or manipulatives to model scenarios:

   • “We’re bakers—if we bake 6 cookies and double the amount, how many do we have?”
   • “We’re farmers with 8 sheep, and we need to split them into two paddocks. Can you halve them?”

3. Quickfire Game:
   Shout out a number (e.g., 5, 8, 10), and students respond with either the double or the half, depending on your command.

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5. Cooldown Worksheet (5 minutes)

Objective: Individual quiet work to consolidate learning.

Distribute “Buzzy Bees” worksheets where students double or halve the number of bees shown in each hive. This is a quiet task that allows you to check their individual understanding before the end of the lesson.

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Key Teaching Notes

• Differentiation: Pair struggling students with a buddy or adjust by focusing on doubles/halves within their ability. Offer trickier numbers (e.g., 11) for more advanced learners.
• Cultural Relevance: Relate examples to aspects of New Zealand life, e.g., doubling sheep on a farm or halving kiwifruit in a lunchbox. Make connections to the contexts students understand.

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Ending the Lesson

Finish by praising effort and curious thinking. Let students know how they will use doubling and halving in future maths adventures. Celebrate their work by displaying their problem-solving on a classroom board.

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Assessment

• Observe and note which students confidently use manipulatives to explain doubling and halving concepts.
• Use completed worksheets to gauge individual understanding.
• Reflect on who may need additional practice before moving to higher-level concepts in future lessons.

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This lesson combines physical interaction, group collaboration, and relatable storytelling, ensuring students remain engaged while learning essential maths skills!