Create a project that uses multiple green flag blocks to make things happen at the same time.
In this module, students use the when green flag clicked block to explore the concept of parallelism: making two or more things happen at the same time. In Scratch, parallelism can mean two or more code stacks running on the same sprite at the same time, causing the sprite to do multiple things simultaneously. Parallelism can also mean two or more code stacks running on different sprites at the same time, causing multiple sprites to do things simultaneously.
This module is available as Google Slides. You candownload the slides as a PDF.