In the chart, Mathematica accurately yields 0.2 at each step if sufficient extended precision was specified at the start. If not, its full output form alerts the user to the precision collapse (step 19 of the blue line). By contrast the non-Mathematica system can only work with 16-digit precision--yet results are produced for any number of steps, however erroneous and whether or not the fixed 16-digit input precision justifies the output.

Mathematica's extended-precision computation (EPC) supports almost any length of integer and precision of real or complex numbers--unlike non-Mathematica, numerical-only systems, which work to machine precision or around 16 digits.

As well as being required for high-precision answers, EPC is often a crucial factor in achieving accurate low-precision answers because intermediate computation stages can drain precision--sometimes dramatically. Complementing EPC, precision tracking is also built into Mathematica.