[bajsejohannes]

A suggestion for the visual area widget: Count the boxes for the user. So in the first box you'd write 1, the second 2, etc. Then it's easy to verify that the numbers are indeed a counting (they increase by 1) and that the calculated are indeed checks out.

I'd write the numbers in gray so they don't dominate the image.

[hsparikh]

Thanks for the feedback. There is a lot of work that still needs to be done to improve the UI for these tools, but our goal is to build a library of such visual tools for tens of relevant topics.