Nice project, a claver way of skipping repeat write of previous math step work and just do little edit for the NEXT step in the Math homework .

github https://github.com/jaltekruse/Free-Math

On a different note: I think for grading purposes of student math home work which is done on a paper, Deep Learning neural network programs will be advanced enough in 5 years that is by 2023 - we will have a $200 flatbed scanner in every class room, as student finish his school work/home work, she can put the papers on scanner, it will sent scanned image to school server which is running Deep Learning software which Grades and home work and record scores in Database for teacher to view .