Hello, I have some feedback which would certainly benefit me and hopefully many others. When I am solving a problem using the in built drawing system, if I then get the wrong answer and click the option to see how it should have been done, my workings disappear so I cannot compare what I did right/wrong with the solution provided by Khan academy. As a tablet user I use the drawing system a lot but it is always a little frustrating when I cannot compare my working without having to utilize some external software. Thanks and keep up the great work!