[user02@FC4 Lesson10]$ cat -n addvalue.c

   1  #include <stdio.h>
   2
   3  int add_values(int a, int b)
   4  {
   5     return(a+b);
   6  }
   7
   8  int main(void)

   9  {
  10     printf("100 + 200 = %d\n", add_values(100, 200));
  11     printf("500 + 501 = %d\n", add_values(500, 501));
  12     printf("-1 + 1 = %d\n", add_values(-1, 1));
  13
  14     return 0;
  15  }

[user02@FC4 Lesson10]$ gcc -o addvalue addvalue.c
[user02@FC4 Lesson10]$ ./addvalue
100 + 200 = 300
500 + 501 = 1001
-1 + 1 = 0
[user02@FC4 Lesson10]$