Mathigon – an interactive, personalized mathematics textbook
Some feedback:<p>There is no help if I get something wrong.  E.g. on the last question on <a href="https://mathigon.org/course/graphs-and-networks/eulers-formula" rel="nofollow">https://mathigon.org/course/graphs-and-networks/eulers-formu...</a> I did not understand the final section's explanation (I have no idea what "the topmost face of the polyhedra becomes the “outside”" is supposed to mean!).  I tried entering a number into the last box and it was wrong.  I entered another - wrong again.  The "chat" thing just said "try 2" and it was right.<p>So why was it 2?  There was no explanation or more help to explain that to me.  I was just told to enter 2 and I did without anything to help me understand more, and then it let me continue.<p>It would be useful if, when someone gets the answers wrong once or twice, that some extra material appears, perhaps with more examples or more step-by-step explanation to help explain why.  No need to show this to everyone - only show it if people are struggling or click on a "tell me more" type expandy thing.<p>As it was, I still do not know why the answer was 2 and I leave mystified and frustrated.<p>Otherwise its very nice - one or two weird moments where I had to click on "reveal all" on Firefox (appears to have not realised I scrolled?)