Capacity In Litres

Overview

Lesson 4 of 7 in “Measuring Tools and Units”. Students estimate, measure and compare container capacity using litres and millilitres, while distinguishing a container’s capacity from the amount of liquid it currently holds.

Learning intentions

• WALT measure and compare capacity using litres and millilitres.
• WALT read a measuring jug scale accurately.
• WALT choose an appropriate unit and record measurements.
• WALT convert between litres and millilitres.

Success criteria

• I can choose litres or millilitres for a measurement.
• I can read a measuring jug scale.
• I can measure carefully at eye level and record the capacity accurately.
• I can convert between litres and millilitres.

Curriculum links

• Measurement: estimate, measure, compare and record capacity using standard metric units.
• Number: use place value and multiplication or division by 1,000 to relate litres and millilitres.
• Mathematical communication: explain measurement choices and justify comparisons.
• Key competencies: thinking; using language, symbols and texts; managing self; participating and contributing.

Lesson structure (30 minutes)

1. 0–4 minutes – Hook and prior knowledge Open with the capacity hook and learning intention. Show a small medicine cup, a drink bottle and a bucket. Ask: “Which unit would make sense for each one—litres or millilitres? How do you know?” Record predictions and introduce the words capacity, amount held, litre and millilitre using pictorial vocabulary.

2. 4–9 minutes – Explicit teaching and demonstration Use the measuring demonstration slides to show that capacity is how much a container can hold, while the amount held may be less. Demonstrate filling a measuring jug, placing it on a level surface and reading the scale at eye level. Emphasise: check the zero, pour steadily, read the bottom of the meniscus where appropriate, and record the unit. Establish that 1 L = 1,000 mL and that 100 mL = 0.1 L.

3. 9–12 minutes – Estimate and plan In groups of four, students examine four classroom containers. They estimate each capacity and decide whether litres or millilitres is the better unit. Display the conversion reference using the Units Conversion Ladder and model one example, such as 600 mL = 0.6 L.

4. 12–22 minutes – Practical investigation Distribute the capacity investigation worksheet to pairs. Each pair measures selected containers using a measuring jug, recording the container, estimate, unit, actual measurement and comparison statement. Students must measure at eye level and repeat one measurement to check reliability. Prompt discussion: “Which container has the greatest capacity?” and “Does the container with the most liquid necessarily have the greatest capacity?” If technology is available, briefly use the virtual number-line modelling slide to represent 0, 500 mL and 1,000 mL and connect the scale to the conversion.

5. 22–26 minutes – Share and reason Pairs compare results with another pair and order their containers from least to greatest capacity. Invite students to explain differences between capacity and the amount currently held. Select examples that reveal common errors, such as confusing 0.5 L with 5 L or reading the jug from above.

6. 26–30 minutes – Plenary and formative check Return to the plenary and success-criteria slides. Students complete the final worksheet questions: convert 750 mL to litres and explain which unit they would use for a swimming pool. Take verbal responses, revisit any uncertainty, and ask students to self-assess against the success criteria.

Resources

• the capacity lesson slide deck
• the capacity investigation worksheet
• the Units Conversion Ladder
• Measuring jugs with clear 100 mL markings
• Clean containers of varied sizes
• Water, trays and cloths or paper towels
• Small cups, bottles and a bucket
• Pictorial vocabulary cards or board illustrations
• Pencils and rulers
• Optional device for a virtual number-line model

Assessment

• Observe whether students select suitable units, read scales at eye level and measure without spilling or starting above zero.
• Check worksheet estimates, measurements, comparisons and conversions, noting whether students record units correctly.
• Use questioning and the plenary to identify misconceptions about capacity, current amount and the relationship between litres and millilitres.

Differentiation

• Support learners with clearly marked containers, 100 mL interval prompts from the Units Conversion Ladder, partially completed worksheet tables and a peer measuring partner.
• Repeat the demonstration in a small group. Use tactile pouring, uncluttered worksheets, large-print scales, pictorial vocabulary and teacher-read instructions for dyslexic learners.
• For EAL learners, rehearse sentence frames: “The capacity is ___ mL”; “___ has greater capacity than ___”; and “I chose ___ because…”.
• Extend confident learners with multi-step problems: combine two containers, find how much more is needed to reach 1 L, or determine the difference between two measured capacities.