HP Prime Miscalculating

[retoa]

I do not know Wolfram Mathematica very good, but in Maxima you can do:

3.6b0^2-4*3.24b0; (3.6b0 is like 3.6e0 but it uses a big float instead of a float)

the result will be:

−2.220446049250313b−16 which means −2.220446049250313e−16 and is also different from 0

To obtain exactly the same result on two different machines they have to work with the same number of bits.

If Wolfram Mathematica works as good as Maxima and the Prime do, then there should be a way to obtain a similar value.
Otherwise it would mean that Wolfram Mathematica can not do all types of mathematical calculations... :-)