A jug with scale labelled 200, 400, 600, 800, 1000.
Marks halfway between each number.
Three buttons to the right of the jug: Fill, Empty, Check.
Click on the Fill button to measure 500 ml.
Click on the Empty button if you have too much liquid.
Click on the Check button to check your answer.
After two wrong attempts, you can click on a 'show' button to see the correct answer.