#include <stdio.h>

int main(void) {
    int eggs;
    printf("How many eggs did your chickens lay today? ");
    scanf("%i", &eggs);
    double dozen = (double) eggs / 12;
    printf("You have %f dozen eggs\n", dozen);
    return 0;

Using (double) allows the output to be a float. Otherwise it will output as an integer
as you are dividing an integer (user input for eggs) by an integer (12). This is just how C works.