Seeing Number Parts

Overview

In this second lesson of the five-lesson unit, students develop number sense by recognising small groups without counting and composing and decomposing numbers to 5. They connect dot patterns, fingers, counters, five-frames and simple number sentences, building on their earlier counting and quantity knowledge.

Learning intentions

• WALT recognise small amounts without counting.
• WALT compose and decompose numbers to 5 in different ways.
• WALT use mathematical language to explain how parts make a whole.
• WALT find a missing part when the whole is known.

Success criteria

• I can subitise groups to 5.
• I can show a number in more than one way.
• I can explain that a whole number is made of parts.
• I can find a missing part.

Curriculum links

• Te Mātaiaho Mathematics and Statistics: Number, first six months — subitising small collections.
• Te Mātaiaho Mathematics and Statistics: Number, first six months — composing and decomposing numbers to 5.
• Year 1 key changes — developing number sense through structured representations, reasoning and mathematical talk.
• Mathsteasers — noticing patterns, explaining thinking and making connections between representations.

Lesson structure (60 minutes)

1. 0–8 min · Welcome and flash subitising. Open with the opening dot-pattern slides and briefly show dot cards for 1–5 for two or three seconds; students say how many they saw, show the amount on their fingers and explain, “How did you see it?” Do not ask students to count the dots after every flash; record whether each child recognises, counts or uses a familiar pattern.

2. 8–18 min · Model parts and wholes. Use counters and a large five-frame to show 4 as 2 and 2, then 4 as 1 and 3. Return to the whole-and-parts modelling slides to display the matching images and sentence, “4 is 2 and 2.” Model the language whole, part, altogether, equal, compose and decompose. Students make each arrangement with counters, fingers or a small five-frame and rehearse: “The whole is __. The parts are __ and __.”

3. 18–33 min · Partner arrangement game. Give pairs counters, dice, dominoes and five-frames. Students roll a die or choose a domino, build the quantity, then rearrange it in another way if possible. They compare arrangements using the Number Bonds Matching Cards as a guide for choosing a target number, representing it with counters and recording matching parts. Prompt: “What stayed the same? What changed?” Partners take turns explaining their thinking rather than simply naming an answer.

4. 33–45 min · Shake and spill. Demonstrate placing five counters in a cup, shaking and spilling them, then separating the two groups. Students work in pairs, record each result on the parts-and-wholes recording sheet and say the matching sentence, for example, “5 is 2 and 3.” Encourage students to look for patterns and turn over or regroup the counters to check whether a different arrangement has already been found. Collect examples such as 0 and 5, 1 and 4, and 2 and 3, without requiring all combinations from every student.

5. 45–54 min · Build the whole. One partner hides some counters under a cup and leaves the rest visible in a five-frame. The other partner identifies the missing part needed to make 5, then checks by lifting the cup. Use the missing-part game slides for two shared examples and sentence frames: “I can see __, so I need __ more to make 5.” Swap roles after each turn. Students who are ready create a hidden part and challenge their partner.

6. 54–60 min · Explain and reflect. Show two final arrangements on the discussion and exit slides. Students think, pair and share how the arrangements show the same whole in different ways. Complete a quick teacher check: flash one familiar pattern to each child or small group and ask for the quantity and explanation. Students complete the final box on the reflection prompt by drawing one way to make 5 and telling a partner the two parts.

Resources

• the complete subitising and composing slide deck
• the parts-and-wholes recording sheet
• Dot cards showing 1–5 in varied familiar arrangements
• Five-frames and counters
• Dice and dominoes
• Cups for shake-and-spill
• Buttons, shells, toy food or other safe classroom loose parts
• Pencils, crayons and a large modelling five-frame
• Optional local pattern photographs or teacher-created arrangements, used respectfully

Assessment

• During flash patterns, note whether students instantly recognise 1–3, recognise familiar arrangements to 5, count, or need support. Ask, “How did you see it?”
• Listen for accurate use of whole, part and altogether during partner work; check whether students connect concrete arrangements with statements such as “5 is 2 and 3.”
• Use the final drawing and missing-part explanation to identify students ready for a new challenge and those needing further work with 1–3 or structured five-frames.

Differentiation

• Support students with quantities 1–3, uncluttered dot patterns, a structured five-frame, fingers and adult modelling. Allow them to respond by pointing, placing counters, drawing or speaking.
• Provide sentence frames and accept explanations in home languages or te reo Māori before encouraging an English mathematical explanation. Pair students thoughtfully so both partners have a speaking and doing role.
• For students ready to extend, ask them to find every way to decompose 5, compare two arrangements, or notice 6 as 5 and 1 more. Ask, “Can you prove you have found them all?”
• Use large, high-contrast cards, reduced visual clutter and extra processing time for students with visual, language, attention or fine-motor needs. An adult may record a student’s explanation.