Here is an easy example to see if your mathematical software deals with floating point correctly.

You want to divide two thirds by five sixths. So you use GNU *bc*

stany@Gilva:~[11:13 PM]$ echo "(2/3) / (5/6)" | bc -l .79999999999999999999 stany@Gilva:~[11:14 PM]$

Matlab, which is arguably better at math then *bc* is, gives me this:

EDU>> (2/3) / (5/6) ans = 0.8000 EDU>>

2*6 / 3*5 = 12/15 = 4/5 = 0.8 so Matlab is correct, and bc is wrong.