With the code:

Code:

#include <stdio.h>
int main(int argc, char *argv[])
{
	int	t	= 1680;
	float	adj	= 1.12;
	int	ires	= (int)(t / adj);
	float	fres	= t / adj;
	int	rires	= (int)(t / adj + .5);

	printf("adj =\t%.20f\n", adj);
	printf("fres =\t%.20f\n", fres);
	printf("ires =\t%i\n", ires);
	printf("rires =\t%i\n", rires);
        return(0);
}

with or without the text shown in red, on Mac OS X 10.9.4, I get the output:

Code:

adj =	1.12000000476837158203
fres =	1500.00000000000000000000
ires =	1500
rires =	1500

which seems to match what you showed us from your Java code.

It is interesting that you're getting the line:

Code:

adj =   1.12000000476837158000

while I'm getting:

Code:

adj =	1.12000000476837158203

But, as I said before, as long as you're performing floating point arithmetic (float, double, or long double) where one of the operands or the result of a division does not have an exact representation may produce a result that is slightly higher or slightly lower than the exact decimal calculation would yield. Any time you are converting a floating point value to integer you need to take care to make adjustments suitable for the results you want given the limitations of floating point arithmetic. (Note that depending on what values you're expecting and the operations that have been performed, adding .5 before converting to int might or might not be appropriate.)

I would assume that C doesn't include a decimal data type because the hardware on which C was initially developed didn't include instructions to process binary coded decimal data (and a lot of hardware today doesn't either).

Have you looked for an open-source version of the dc utility source to see how it handles arbitrary precision arithmetic?

I don't have any experience with it, but have you looked at XBCD_Math?