This started as a school project. I needed to make an app and a website to go along with it. We had freedom to do whatever we wanted, and since I was very much interested in machine learning at the time, I figured I would do an app that would read the equation using OCR, and then solve it.
Later on, when I started making the app, I realized how horribly bad the OCR is at recognizing symbols.
Even huge symbols were misinterpreted or not even interpreted.
After a while, I got an idea to create a solver for the "worded" equations. Where numbers and operators are written in words, such as "TWENTY" and "MINUS". OCR was much better at interpreting equations in this format.
And so I found a way to parse "word" numbers into their digit form, and I wrote a simple algorithm to parse the OCR output and solve the equation.
As a result, the created app could be called a gimmick, useless, but it was fun, and it worked quite well.