Wrong calculator function

[reallyinvincible]

All functions just return addition of the number instead of their respective operations

[alejandrocq]

Hi! Can I take this?

[reallyinvincible]

Sure :)

[alejandrocq]

Oh! I just realised that this was already fixed in #10. This issue can be closed.

[KeshavAnandBhagat]

Hi, Please assign me this issue if it still exists?