C code - 9 lines

Link:

C, pasted on Jul 13:

#include <stdio.h>

#define HALVE(n) n / 2

int main(void)
{
    printf("Half of 5 + 5 is %d\n", HALVE(5 + 5));
    return 0;
}

Output:

1	Half of 5 + 5 is 7