How to implement mathematical formula keyboard display and input in Android

Question

The above picture comes from Shensuanzi student version app. I would like to ask what are the ideas for such a keyboard and what open source libraries can implement it

Answer 1

Google search

scientific calculator android github

Finding a library should solve your problem
https://github.com/anubhavshr...

As for the keyboard, you have to write it yourself. This seems to be missing