Different trig algorithms in CAS and Home?

[chromos]

(01-04-2018 08:46 AM)Dieter Wrote:  The Prime (like other 12-digit HP calculators) internally works with 15 (!) digits.
Dieter

Thank you for reply, Dieter, even it didn't answer my question why current calculator doesn't have better precision (or accuracy - my knowledge of english isn't capable differentiate these terms) than calculator 40 years old.

How do you know the HP Prime works with 15 digits internally? There is only one information about Prime precision in user manual (both Quick Start Guide and User Guide Phase 2):

• On the other hand, non-CAS calculations, such as those performed in HOME view or by an app, are numerical calculations and are often approximations limited by the precision of the calculator (to 12 significant digits in the case of the HP Prime).
  

And if I try:

• 1/9-.111111111111 // i.e 12 times number '1'
  

then I get 0 instead of 1.11e-13.