lesson
How heavy is it?
Read with an adult. You can say, point, draw or write your answer.
1 · Learn
Which object is heavier? Scales help us check. The measurement we record is called mass. A bigger-looking object is not always heavier.
We use grams for small masses and kilograms for larger ones. One kilogram is 1,000 grams. Keep the units the same when you compare two readings.
2 · Worked example
A large empty box can have less mass than a small full jar. I measure rather than deciding from size alone.
3 · Your turn
Which has greater mass: 300 g or 500 g? What is the difference?
Check your answer
500 g. The difference is 200 g.
4 · Apply your learning
With an adult, estimate which safe object has greater mass, then use suitable scales to check. Choose grams or kilograms. Read the nearest marked unit together and write the unit beside your measurement.
Adult guidance and safety
Use practical objects before symbols. Read the task aloud when needed and ask the child to explain, not just name an answer. Revisit with different examples; one successful answer is not proof of fluency.
Open your writing and drawing pad
Write, draw or show your working. Use a mouse, pen or finger. This pad is not a submitted answer.
Not saved to your account. Download your drawing as PNG and your typed notes as TXT before leaving or refreshing. They are separate files. Do not enter private information.
Open a picture saved on this device to draw on it again. Opening replaces the drawing, but Undo can restore it. PNG only, up to 4 MB and 4096 × 4096 pixels. The picture stays in this browser; it is not uploaded. Paper lines in a saved picture become part of that picture.
Clear the drawing? Your typed notes will stay. You can undo this action.
Your pad is empty.
Open a UTF-8 TXT file from this device, up to 40 KB and 10,000 characters. It stays in this browser. Opening can be undone until you type again. Downloads keep a new copy; they do not change the file you opened.
Replace the notes on this page with the opened file? Download the current notes first if you want to keep them.
Typed notes are not submitted answers.
Practice this lesson
Lesson resources
Browse the available practice activities and worksheets for this lesson.
Your progress