Coding Compile time Error

[ghost]

Description of the Issue:
There is an undefined variable in file num.c in the project finalpractical.

Why this issue needs to be fixed?
An undefined variable in any program leads to crashes and failures in a program.
Also, if this is a part of a larger project then it will damage and hamper he lager project.

How to reproduce in case of bug?
First, clone the repository and navigate to it.
Check the compilation error
Correct it and commit the changes.

Additional Notes/Environment Information:
OS - Linux OS
Compiler: C Compile
@vpriyapm