Tools and Units

Overview

In this lesson, students learn to choose appropriate metric units and measuring tools for mass and capacity. They explore real instruments, make predictions, and sort objects by the unit and tool they would use.

Learning intentions

Students will be able to:

• identify and describe common metric units for mass and capacity
• match objects to the most suitable unit (grams, kilograms, milliliters, litres)
• choose the most suitable measuring tool for given situations
• use careful measuring language (more/less, about, near) when comparing quantities

Success criteria

I can…

• name grams and kilograms for mass, and milliliters and litres for capacity
• explain which tool I would use (kitchen/balance scale, measuring jug, graduated cylinder)
• sort cards correctly by unit and tool for everyday objects
• answer an exit ticket by matching each object to the correct unit and tool

Curriculum links

• Measurement: using metric units for mass and capacity and selecting the appropriate units
• Using measuring tools with accuracy in everyday contexts
• Communicating measurement reasoning using correct mathematical language

Lesson structure (45 minutes)

1. 5 min – Activate knowledge (Class discussion + quick demo) Show two items (e.g., an apple and a small bag of sugar). Ask: “Would we use grams or kilograms?” Repeat with a cup of water: “Millilitres or litres?” Record student ideas on the board as two columns: mass and capacity.

2. 8 min – Mini-teach: units and tools Introduce and demonstrate:

• Mass: grams and kilograms; kitchen scales or balance scales
• Capacity: milliliters and litres; measuring jug or graduated cylinder Focus on what each tool is for and how units match the situation (small amounts usually millilitres/grams; larger amounts usually litres/kilograms). Emphasise that tools help us measure fairly and compare results.

3. 12 min – Measurement station rotation (Prediction then check) Set up 4 stations. Students rotate in pairs with a timer. At each station they:

• predict the unit and tool for a displayed object/problem card
• record their prediction on a response sheet
• handle the tool briefly to confirm (e.g., check the unit markings on the jug/cylinder, observe scale dial/labels) Station examples:
• Station A (Mass): kitchen scale with a small item (e.g., 150 g target)
• Station B (Mass): balance scale with a larger item (e.g., “more than 1 kg?”)
• Station C (Capacity): measuring jug with a small pour (e.g., “under a litre”)
• Station D (Capacity): graduated cylinder with a precise small volume (e.g., “millilitres needed”)

4. 6 min – Whole-class debrief (Share and justify) Invite a few groups to explain one prediction and their reasoning: “I chose millilitres because…” “I chose kilograms because…” Reinforce correct tool-choice language.

5. 10 min – Sorting task (Unit + tool matching) Give each group a set of object cards and tool/unit cards. Students sort into four categories:

• grams + mass tool
• kilograms + mass tool
• millilitres + capacity tool
• litres + capacity tool They must write one sentence per category: “We would measure this with ___ because the unit fits the size of the quantity.”

6. 4 min – Exit ticket (Individual formative assessment) Students complete a short matching task:

• 2 items for mass (grams or kilograms, plus tool)
• 2 items for capacity (millilitres or litres, plus tool)
• 1 “odd one out” where they choose the incorrect unit/tool and explain why (one simple reason)

7. 0–2 min – Pack-up and quick check-in Collect exit tickets. Ask one final question: “When measuring a small amount of juice, which capacity unit is most likely?”

Resources

• Kitchen scale and/or balance scales
• Measuring jug(s) with clear millilitre and litre markings
• Graduated cylinder(s) with clear millilitre markings
• Object/problem cards (e.g., apple, bag of rice, bottle, cup of juice, bucket of water)
• Prediction sheets for station responses
• Sorting card sets (units and tool options)
• Timer for rotation
• Exit ticket slips and pencils
• Board or chart paper to record unit/tool choices

Assessment

• Formative observation during station rotation: students’ predictions and reasoning
• Group sorting task: accuracy of unit and tool matching
• Exit ticket: individual understanding of correct unit and tool selection for mass and capacity

Differentiation

• Support:
• Provide a “unit-to-tool” word bank and sentence starters (“I chose ___ because the amount is small/large”)
• Use fewer sorting cards at first; gradually add more as confidence grows
• Pair students strategically so they can discuss predictions
• Extension:
• Add challenge cards with ambiguous choices (e.g., “about 900 ml” or “about 1 kg and a bit”) and ask students to justify their decision
• Ask some students to rank three items from smallest to largest volume/mass and state the likely unit
• EAL/SEN:
• Use visuals on cards (e.g., icon for small bottle vs large bucket)
• Allow oral responses for the exit ticket reasoning, recorded by the teacher if needed
• Keep instructions short and repeat key terms: grams, kilograms, millilitres, litres, measure, tool