Here is a general challenge that can be used at any level and any class. This can be as quick or as long as you see fit. The goal here is not to provide much upfront. Just let the kids build. Let them be in charge of their learning and how to showcase what they know.

This is where the magic happens. Not forcing them to build something that they think you (teacher) want, but something that helps them express their own learning.

Once the builds are complete then you can have them make a Flipgrid, take a picture of the model and label on a Google Slide or Onenote Tab, create a Thinklink, etc. The possibilities are really endless for the expression of learning. You could simply have them set it on a piece of paper and draw arrows with labels.