Pi

#include <stdio.h>
#include <math.h>

int main()
{
    int number, lower_limit, upper_limit, divisor;
    long double division_result, subtraction_result, absolute_value, lowest_value;

    lowest_value=1;

    for(number=100; number<=10000; number++)
    {
        lower_limit=(int)(number/3.2);
        upper_limit=(int)(number/3.1);
        for(divisor=lower_limit; divisor<=upper_limit; divisor++)
        {
            division_result=(long double)(number)/(long double)(divisor);
            subtraction_result=division_result-M_PI;
            absolute_value=fabsf(subtraction_result);
            if(absolute_value<lowest_value)
            {
                lowest_value=absolute_value;
                printf("%i / %i = %.9LF\n", number, divisor, division_result);
            }
        }
    }
    return(0);
}

/*
100 / 31 = 3.225806452
100 / 32 = 3.125000000
101 / 32 = 3.156250000
104 / 33 = 3.151515152
107 / 34 = 3.147058824
110 / 35 = 3.142857143
179 / 57 = 3.140350877
201 / 64 = 3.140625000
223 / 71 = 3.140845070
245 / 78 = 3.141025641
267 / 85 = 3.141176471
289 / 92 = 3.141304348
311 / 99 = 3.141414141
333 / 106 = 3.141509434
355 / 113 = 3.141592920
*/