Exploring Capacity Together

Overview

Across two short lessons, students investigate capacity by filling, pouring, comparing and ordering containers. They build on everyday experiences with “full”, “empty” and “half-full”, while learning to explain comparisons using practical evidence and the language of capacity.

Learning intentions

• WALT compare the capacity of different containers.
• WALT use everyday language to describe how much a container can hold.
• WALT order containers from holds the least to holds the most.
• WALT explain how we know which container has greater capacity.

Success criteria

• I can use a fair test to compare containers.
• I can use words such as full, empty, more, less, holds more and holds less.
• I can order containers by their capacity.
• I can explain my thinking by showing or describing what I did.

Curriculum links

• Mathematics and Statistics — Measurement: exploring and comparing capacity in meaningful contexts.
• Mathematics and Statistics — using mathematical language, representations and practical evidence to communicate thinking.
• Mathsteasers — developing higher-order thinking through explaining, justifying and comparing solutions.
• Mathsteasers / Alignment — connecting practical mathematical investigation with classroom learning.

Lesson structure — Lesson 1: Which Holds More? (20 minutes)

1. 0–3 min · Hook. Teacher shows two different containers and asks, “Which one will hold more water? How could we find out?” using the capacity hook and question slide. Students make a quiet prediction, then share a reason with a partner.

2. 3–6 min · Teach the language. Teacher introduces or revisits empty, full, holds more, holds less and same amount, modelling gestures and showing the capacity vocabulary slides. Students repeat the words and use them to describe the containers.

3. 6–14 min · Practical investigation. Teacher places two containers, a small cup for measuring, a tray and water at the table; teacher models filling the same cup each time to make a fair comparison. Students work in three pairs, predict which container holds more, then fill and count how many small cups each container holds.

4. 14–17 min · Compare results. Teacher records each pair’s results on the board and asks, “Did our predictions match? What evidence do we have?” Students compare their numbers and explain which container holds more or less.

5. 17–20 min · Plenary check. Teacher displays a new pair of containers on the first-lesson discussion and review slide and asks students to show thumbs up for “holds more” and thumbs down for “holds less”. Students give one spoken sentence explaining their choice.

Lesson structure — Lesson 2: Ordering Capacity (20 minutes)

1. 0–3 min · Reconnect. Teacher revisits the investigation photographs or drawings and asks, “What did we do to make our comparison fair?” using the retrieval and fair-test slide. Students recall that the same small cup was used each time and orally rehearse holds more and holds less.

2. 3–6 min · Predict and discuss. Teacher shows three containers and asks students to put them in order from least capacity to greatest capacity. Students discuss their predictions with a partner and explain what features helped them decide.

3. 6–14 min · Order by testing. Teacher provides the three containers, a small identical cup, water and a tray for each pair. Students test the containers, count the cups needed, and place them in order from holds the least to holds the most; they record the result on the capacity investigation sheet.

4. 14–17 min · Explain and challenge. Teacher asks, “Could a tall, thin container hold less than a short, wide container?” and invites students to demonstrate. Students compare shape with capacity and explain why looking tall does not always mean holding more.

5. 17–20 min · Exit reflection. Teacher displays the final prompt on the ordering and reflection slide. Students complete the sentence, “The container with the greatest capacity is ___ because ___,” orally or by drawing and dictating their response on the capacity reflection section.

Resources

• the capacity investigation slide deck
• the capacity investigation sheet
• Three to six transparent, unbreakable containers of different shapes and sizes
• Small identical cups for measuring
• Water
• Trays or towels for spills
• Board or large paper for recording results
• Camera or tablet for optional photographs of the investigation

Assessment

• Listen for accurate use of capacity vocabulary during predictions, testing and partner explanations.
• Check whether students use the same-sized cup consistently and can order containers using evidence rather than appearance alone.
• Review the investigation sheet and reflection for a comparison, an ordered result and a simple explanation.

Differentiation

• Support students with visual vocabulary cards, gestures, sentence frames such as “___ holds more than ___ because ___”, and an adult or peer partner to help count cups.
• Use only two containers initially for students who need reduced cognitive load; pre-mark a starting level and model filling without spilling.
• Encourage confident students to test whether two containers hold the same amount and to suggest another fair way to compare them.
• Provide accessible containers with wide openings and handles where needed; offer drawing, pointing, home-language discussion and oral dictation for students developing English or fine-motor skills.
• Keep water in shallow trays, model safe carrying and provide a dry alternative using counters or rice if sensory or physical needs make water unsuitable.