3 7关于#浮点数#的问题，如何解决？(语言-c语言)

Question

．编写程序，将浮点数100.453627分别四舍五入到十分位、百分位、千分位、万分位后输出。

Answer 1

#include <stdio.h>
int main()
{
    double num=100.453627;
    printf("%.1f\n",(int)(num*10+0.5)/10.0);
    printf("%.2f\n",(int)(num*100+0.5)/100.0);
    printf("%.3f\n",(int)(num*1000+0.5)/1000.0);
    printf("%.4f\n",(int)(num*10000+0.5)/10000.0);
    return 0;
}