Calculator accepts data type of text but this is not how a calculator works

[Code-Recursion]

1.) calculator is accepting text as the data type but a calculator can only work with numbers.
fix that.

Do not change input type to text handle the input with regex

[akhilarjun]

I will take this up

[skamp91]

Hey :) I would also gladly work on it, if that is possible .
GoodRegards

[Code-Recursion]

Fixe on #17