Computer simulations can represent real or imaginary situations. They allow users to study or try things that would be difficult or impossible to do in real life.

Maths Simulations online

Grow Alien plants Change the variables to grow Universe record breaking plant.
There are four plants that need feeding:

Interpreting a line graph
Bath time with Archimedes Turn the tap on, turn the tap on, put the plug in, take the plug out, Archimedes gets in and out of the bath...a line graph is drawn in real time. Interpret the graph.