Hey everybody I am working on a program in c that tells you the least number of coins needed for any given amount of money. I have a program written that works for for every amount I have tested except for $4.20.

Here is my code:

```
#include <cs50.h>
#include <stdio.h>
#include <math.h>

int main(void)
{
    float f;
    int n, x, y, z, q, s, d, t;

    do {
        printf("How much change do you need?\n");
        f = GetFloat();
    } while(f <= 0);

    {
        n = (f * 100);
    }

    q = (n / 25);
    x = (n % 25);
    y = (x / 10);
    z = (x % 10);
    s = (z / 5);
    d = (z % 5);
    t = (q + y + s + d);

    {
        printf("%d\n" ,t);
    }
}

```

The strange thing is when I input 4.20 the output is 22 instead of 18 (16 quarters and 2 dimes). I did some sleuthing and found that the problem is with my variable x. When I input 4.2, x gives me 19 and not 20 like it should. I tried other cases that I thought should have produced the same problem like 5.2 and 1.2 but it worked correctly in those cases. It might be a rounding issue but I would think that same error would also happen with those similar values.

Does anyone have an idea about why this might be happening? 

PS I am fairly new to coding and I haven't gotten much formal instruction so I also welcome tips on better indentation and formatting if you see anything obvious.