Mathematics · Year 5

Active learning ideas

Capacity Conversions (ml, l)

Active learning works for capacity conversions because students need repeated hands-on experiences to internalize the scale difference between millilitres and litres. Moving liquids between containers helps them feel the relative sizes of 1 ml and 1 l, which supports accurate mental calculations and problem solving.

• National Curriculum Attainment Targets
• KS2: Mathematics - Measurement

• 20–40 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 25 min · Pairs

Pairs Pouring Relay: Unit Matches

Pairs take turns pouring water from 100 ml beakers into a 1 litre jug until full, recording how many pours equal 1 litre. They then convert given amounts like 2.3 litres to millilitres and verify by pouring. Switch roles after each conversion.

Explain how to convert 750 ml into litres.

Facilitation Tip

During Pairs Pouring Relay, circulate and ask guiding questions such as 'How many of your 100 ml cups are needed to fill the litre jug?' to reinforce the 1000 ml total.

What to look for

Present students with three cards: one with '1500 ml', one with '0.5 l', and one with '3.25 l'. Ask students to write the equivalent measure for each card in the other unit on a mini-whiteboard. For example, '1500 ml = 1.5 l'.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Stations Rotation
• 35 min · Small Groups

Small Groups: Recipe Totaliser

Provide recipes with mixed ml and l amounts. Groups convert all to litres, calculate totals, and decide if a jug holds enough. They scale the recipe by 1.5 and reconvert, presenting findings.

Analyze a recipe to determine the total capacity needed in litres.

Facilitation Tip

In Small Groups Recipe Totaliser, provide measuring jugs marked in both units so students can cross-check their conversions while scaling ingredients.

What to look for

Give students a small slip of paper. Ask them to write down one thing they learned about converting between millilitres and litres today. Then, pose a problem: 'A jug holds 2 litres of water. How many 250 ml cups can be filled from the jug?'

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Stations Rotation
• 40 min · Whole Class

Whole Class: Capacity Estimation Line-Up

Students estimate capacities of classroom containers in litres, then measure using jugs and convert results. Line up estimates versus actuals on a class chart, discussing discrepancies.

Construct a scenario where converting between ml and litres is essential.

Facilitation Tip

For Capacity Estimation Line-Up, allow students to handle both millilitre and litre containers before ordering them, so they connect the physical size to the numerical value.

What to look for

Present a scenario: 'A recipe calls for 500 ml of juice, but you only have a 1-litre measuring jug. How would you measure the juice? Explain your steps.' Facilitate a class discussion where students share their strategies and reasoning.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Stations Rotation
• 20 min · Individual

Individual: Conversion Puzzle Cards

Students draw cards with problems like '3.4 l = ? ml' and solve on mini-whiteboards. Match conversions to scenario cards, such as filling a fish tank.

Explain how to convert 750 ml into litres.

What to look for

Present students with three cards: one with '1500 ml', one with '0.5 l', and one with '3.25 l'. Ask students to write the equivalent measure for each card in the other unit on a mini-whiteboard. For example, '1500 ml = 1.5 l'.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teachers should avoid rushing to abstract rules. Instead, anchor conversions in physical actions: pouring, filling, and comparing. Research shows that students who manipulate real containers before writing equations retain the relationship better. Emphasize the decimal shift when moving from litres to millilitres, using place value language consistently to prevent errors like multiplying by 10 instead of 1000.

By the end of these activities, students will confidently convert between millilitres and litres without hesitation. They will explain their reasoning, choose appropriate units for real-world tasks, and apply conversions to solve practical problems such as scaling recipes or filling containers.

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Watch Out for These Misconceptions

• During Pairs Pouring Relay, watch for students who miscount the number of 100 ml pours needed to fill 1 litre.

  Have the pair recount out loud together, placing a counter in a cup for each 100 ml poured, until they reach 10 counters and see the total is 1000 ml.

• During Recipe Totaliser, watch for students who convert litres to millilitres by multiplying by 10 or 100.

  Ask them to pour 1 litre into the 1000 ml cups and group the cups into hundreds to see the three zeros shift, reinforcing the 1000 multiplier.

• During Recipe Totaliser, watch for students who ignore unit labels in a recipe and measure everything in millilitres.

  Pause the group and ask them to read each ingredient aloud, then convert it together before measuring, highlighting the importance of matching units to the container.

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Methods used in this brief

• Stations Rotation