adding a basic calculator

[kumarmanishrai]

No description provided.

[yxshrraj]

can you please assign me this issue @kumarmanishrai sir . I know how to build calculator using flutter.

[dhairyajain29]

can you assign me this issue? @kumarmanishrai

[Priyanshu-ai902]

Hi @kumarmanishrai I am interested in this issue
Will you please assign me this issue

[Muskanmehra24]

I want to contribute, please assign me this.

[thesumitkrsingh]

i want to work and learn git and how to make contribution assign me I know the basic level of java

[anuska2772]

I wan to contribute in this issue. So please @kumarmanishrai assign me this issue.