rand command line concurrency programming

Hi i've got some problems with generating random numbers with concurrency programming, on exit() i would like ti use rand -M 6 but i don't know how, i've tried to use rand() in some ways but the childrens always returns the same number. Thanks a lot.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/sysinfo.h>
#include <sys/wait.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#define NUM_KIDS 5

int i, sum;

int main()
{
    pid_t child_pid;
    int status;

    for (i=0; i<NUM_KIDS; i++) {
        switch (child_pid = fork()) {
        case -1:
            /* Handle error */
                fprintf(stderr,"Error #%03d: %s\n", errno, strerror(errno));
                break;

        case 0:
            /* Perform actions specific to child */

        printf("Hi, my PID is %d\n", getpid());

        exit(/*here i'd like to use rand -M 6*/);
        printf("Hi, my PID is %d and you should never see this message\n", getpid());
        break;

        default:
            /* Perform actions specific to parent */
            printf("I'm the proud parent with PID %d of a child with PID %d\n", getpid(), child_pid);
            break;
        }
    }

    i = 0;

    while ((child_pid = wait(&status)) != -1) {
        printf("PARENT: PID=%d. Got info of child with PID=%d, status=%d\n",
               getpid(), child_pid, status/256);
        sum += status/256;
    }
    if (errno == ECHILD) {
        printf("In PID=%6d, no more child processes, sum: %d\n", getpid(), sum);
        exit(EXIT_SUCCESS);
    }
    return 0;
}