Over three lessons, Year 5 pairs turn what they know about the water cycle into a working model in Scratch, on class accounts the teacher manages. The teacher provides a starting project with a sea, hills, a sun sprite and a slider for sun strength, and pairs write the rest: vapour sprites that rise from the sea faster when the sun is stronger, a cloud that grows each time vapour reaches it, and rain that starts once the cloud's water variable passes a level the pair chooses, then runs down the hill into the river and back to the sea. Pairs test their model by moving the slider and checking it behaves as they expect, then fix it when it does not, for example when the cloud rains for ever because its variable never goes down. In the last lesson pairs try each other's models and write under their own what it shows about the cycle and one thing real clouds do that it leaves out.
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.