print_double.c

// Example compilation:
// gcc print_double.c -std=c99 -Wall -Wextra

#include <stdio.h>

int main(void) {
    double num;

    num = 0.25; printf("%f %a\n", num, num);// 0.250000 0x1p-2
    num = 0.50; printf("%f %a\n", num, num);// 0.500000 0x1p-1
    num = 0.75; printf("%f %a\n", num, num);// 0.750000 0x1.8p-1
    num = 0.10; printf("%f %a\n", num, num);// 0.100000 0x1.999999999999ap-4

    return 0;
}