Mathematics
Intermediate
50 mins
Teacher/Student led
Learning Goals
Learning Outcomes
Lesson Files
+80 XP
What you need:
IWB/Projector/Large Screen
Kitchen scale

Mass: Weighing in Grams and Kilograms

Learn to read mass on a weighing scale in grams and kilograms, and discover when each unit makes sense for different objects.

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    1 - Getting Started ~4 mins

    Illustration for Getting StartedLook at the real scale on the front desk. There is a stack of copybooks sitting on it. Is that heavy or light? What does the scale say?

    Hands up: which of these do you think is heaviest — a feather, your Maths book, or a bag of flour?

    👇 Mark your steps as done as you complete them.

    +5 XP

    2 - Watch and Notice ~8 mins

    Illustration for Watch and NoticeWatch as four real objects are weighed at the front, one at a time. Notice the number on the scale for each one, and notice which unit fits best.

    • A Maths book
    • The class register
    • A bag of flour
    • A feather
    Key point

    Keep an eye out: once an object reaches 1,000 g, that is the same as 1 kg. So 2 kg is the same as 2,000 g.

    👇 Mark your steps as done as you complete them.

    +10 XP

    3 - Try It Together ~11 mins

    We will predict, then weigh. First we weigh a lunchbox. Then a pencil case. Then a stack of three Maths books. Before each one goes on the scale, we say our guess out loud.

    Key point

    For each object: write down your prediction first, then read the actual mass off the scale, then see how close you were.

    How close can we predict the mass of everyday classroom objects before we weigh them?

    ['Look at the object and write your prediction in grams.', 'One pupil places it on the front scale and reads the mass aloud.', 'The class agrees the reading and records the actual mass.', 'Work out how far off the prediction was.']

    Record: three-column table: object, prediction (g), actual (g)

    Share back: class reads each actual mass aloud and reconciles any disagreement

    +15 XP

    4 - Write Each Mass and Its Unit in Your Copy ~3 mins

    COPYBOOK MOMENT

    In your maths copy, write each object we weighed on its own line, with its mass and the unit the scale showed.

    • Maths book
    • Register
    • Flour

    Then underline the unit you would choose for each object if you could only use one, and be ready to say why.

    +10 XP

    5 - Class Challenge ~8 mins

    Key point

    Five real objects will pass around the room: a lunchbox, a pencil case, a glue-stick tub, a stapler, and a full water bottle. Weigh each one on your group's scale and write its mass in grams. If an object reaches 1,000 g or more, write it in kilograms too — the water bottle might.

    Stretch: stack three Maths books, estimate the whole stack first, then weigh it and check how close you were.

    Hands-on Task

    +15 XP
    Pupil practice
    Module 4 · Measures: Length, Mass, Capacity, Area, Volume Measures
    Lesson 56 · Mass: Weighing in Grams and Kilograms
    Download Activity Book page (PDF)
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