Calculation of determinant on HP-15C

[NumberJack]

Hi everyone,

I computed the determinant of a 4x4 matrix on the HP-15C. All coefficients of the matrix are small integers. I know the determinant is 0, but the HP-15C returns "2.1000 -10" in the display, which is a very small number but not 0.

So my question is whether the HP-15C calculates always a numerical approximation of the determinant even when the coefficients of the matrix are small integers? Is there a way to get the "correct" determinant?

Thanks!