Kalevipoeg posted,

Quote:

I have compared f [n] of the 12C and fix [n] of the 11C.
For example we have a number 0.0012345

f [2] of the 12C gives 0.001

whereas

f fix [2] of the 11C gives 1.23x10^-3

f [0], f [1], f [2], and f [3] __all__ display 0.0012345 as 0.001 on the HP-12C, as do the HP-10B, HP-14B, HP-17B, and HP-17BII. In effect, 0.001 is a "FIX 3" format.

That's a nice bit of insight into design principles of HP's business- and scientific-calculator models: The business calculators offer a limited choice of *selectable* display formats:

- The HP-12C offers FIX [0]-[9] and SCI [6] (limits of 10-digit display)

- The HP-10B offers FIX [0]-[9].

- The HP-14B, HP-17B, and HP-17BII offer FIX [0]-[11] and ALL.

Of course, if the magnitude of a number is outside the range of the display using a FIX format, scientific notation with a base-10 exponent will be utilized. For numbers of small non-zero magnitude, these models will simply extend a FIX display format with more decimal digits as needed until the number can be displayed as a non-zero value.

The scientific models, by contrast, offer selectable scientific notation with a *designated number of decimal digits* -- SCI [n] and ENG [n], n = 0-9 or 0-11, as appropriate. So, they will revert to scientific notation with the same number [n] of decimal digits, if FIX [n] cannot represent a non-zero value using only [n] decimal digits.

So, why don't the HP business-calculator models use the procedure of the HP scientific-calculator models? Because to do so would often invoke a non-selectable display mode, and that scientific notation is generally avoided in business applications unless absolutely necessary.

There you have it. BTW, I prefer the procedure of the scientific models, but one should recognize that it is based on their built-in capabilities.

-- KS

*Edited: 14 Oct 2006, 9:49 p.m. *