To separate Fraction and Digit from Number in axapta like number is 878778.3000 and you want to get 878778 and .300 then below code can help you to get the same.
qty t=878778.3000;
str _amount = strFmt("%1",num2str(t,0,1,0,0));
boolean decimals;
TextBuffer txtAmount = new TextBuffer();
txtAmount.setText(_amount);
if (txtAmount.find("^[0-9]+$")) // Regular expression inside the find method
{
decimals = true;
}
info(strFmt("%1 -- %2",trunc(t),frac(t)));