This project is an incomplete version of this one: https://scratch.mit.edu/projects/279021214/ Here is a video tutorial playlist that you can use to help you: https://www.youtube.com/playlist?list=PLSgUBfi51ulfm4vuHjREnwRx8ig4Jvkso Educators, you can find supporting resources here:
NRICH Lesson Idea: https://nrich.maths.org/9941 Hot Air Balloon Resource: http://www.soidergi.com/2018/07/coming-out-of-air-balloon-vector/png-striped-hot-air-balloon-vector/