Hundreds grouping

Overview

In this lesson, students explore how many hundreds are in numbers by physically grouping objects into bundles of 100. They practise making, counting, and explaining groups of 100 using manipulatives and simple number sentences.

Learning intentions

Students will be able to:

• Understand that a hundred is a group of 100 ones.
• Create groups of 100 using manipulatives (bundles/cubes/place value blocks).
• Count how many groups of 100 are in a larger number (without needing to use full place value notation yet).
• Explain their thinking using words and pictures.

Success criteria

• I can make a bundle of 100 using manipulatives.
• I can show a number as groups of 100 (for example, “3 groups of 100”).
• I can count the hundreds groups accurately and confirm my result.
• I can explain how I grouped the objects.

Curriculum links

• Place value: recognising and grouping into hundreds and ones using concrete materials.
• Number and algebra: counting by tens and using structure to support counting by hundreds.
• Mathematical reasoning: explaining how answers were made and checked using models.
• Representing: using concrete representations to show numbers and groups.

Lesson structure (30 minutes)

1. 3 minutes — Quick launch (link to previous learning)

• Show a “hundred bundle” already made (100 straws/cubes/ten rods grouped into one hundred).
• Ask: “What does it mean when we say ‘one hundred’?” “How many ones make one hundred?”

2. 7 minutes — Model and guided practice

• Display a number card (teacher-chosen, accessible for Year 1–2, such as 120, 200, 345, or 400 depending on readiness).
• With the class, build the number using place value blocks: make groups of 100, then add extra tens/ones if needed.
• Use prompts: “I have one group of 100. What number does that part represent?” “How do we know it’s 100?”

3. 12 minutes — Stations: build and count hundreds

• Split the class into two or three stations (or two groups at a time), rotating after 6 minutes.
• Station A (hands-on): Students receive a mat with a target number and build with bundles of 100 and loose ones.
• Station B (picture/model): Students draw or use number cards to show “__ hundreds” and remaining parts.
• Teacher circulates with a checklist of confidence: able to correctly form 100, then correctly state the number of hundred groups.

4. 5 minutes — Share and reasoning check

• Select 3–4 students to show their model at the front (or use a document camera).
• Ask: “How many groups of 100 did you make?” “How did you check?”
• Reinforce sentence frames: “I grouped ___ into hundreds. That makes ___ groups of 100.”

5. 3 minutes — Exit ticket (quick check for understanding)

• Each student receives a small task card: “Show ____ as groups of 100” (one number appropriate to their level).
• Students either build with 100 bundles for a short moment or mark on a picture “__ hundreds”.

Resources

• Place value blocks or base-ten materials (hundreds flats/ones cubes).
• Bundles of 100 manipulatives (straw bundles, paper squares, counters) and loose ones.
• “Hundreds grouping” mats with blanks for: hundreds groups + remaining.
• Number cards for target numbers (range suited to Year 1–2 readiness).
• Visual sentence frames (e.g., “I have ___ groups of 100.”).
• Doc camera/board markers for sharing student models.
• Exit ticket cards and pencils/crayons.
• Timer for station rotations.
• Optional: mini whiteboards for quick “hundreds count” responses.

Assessment

• Teacher observation during stations: correct formation of a bundle of 100 and correct counting of hundreds groups.
• Exit ticket review: can students represent the number as “__ groups of 100” accurately.
• Oral questioning during share time: students explain how they grouped and checked.

Differentiation

• Pair students for support: choose a mixed-support pairing where one student can model careful counting and one may need more scaffolding.
• EALD support: provide sentence starters and allow pointing/gestures; use consistent visual language (“one hundred”, “hundreds groups”).
• Neurodivergent support: use clear, predictable station routines; reduce distractions; provide a small “needed help” card (e.g., “Show me how to make 100”).
• Scaffolds for readiness:
• For students needing extra support: use numbers that are exact hundreds first (100, 200, 300) or close (e.g., 120).
• For more confident learners: include numbers with additional parts beyond hundreds (e.g., 345) while still focusing on counting hundred groups.

Extension (optional)

• Advanced learners: give a larger number (within their ability) and ask, “How many groups of 100 are there?” then “How many are left over?” Students may write a simple equation using words (for example, “There are ___ hundreds and ___ left”).