(Trivia?) Display setting

[Kiyoshi Akima]

Name an HP-manufactured RPN calculator that, when set to FIX 2 display mode (and with any fraction mode turned off), does NOT display 0.01 when displaying the result of 70 1/x.

[David Hayden]

My 30b in RPN mode with FIX 2 displays 0.014. Looks like it displays 2 significant digits. Enter 0.000033 and that's what it displays.

On pages 2 and 3, the 30b manual says that the FIX=N value is "the number of digits displayed to the right of the decimal point."

The 20b displays 0.01.

Dave

[Kiyoshi Akima]

Correct. I ran across this earlier today when I wanted exactly five digits to the right of the decimal point and couldn't get them.

I'm trying hard to like the 30b. It's small, fast, and then something like this pops up...

[Karl Schneider]

Quote:

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My 30b in RPN mode with FIX 2 displays (1/70) as 0.014. Looks like it displays 2 significant digits. Enter 0.000033 and that's what it displays.

On pages 2 and 3, the 30b manual says that the FIX=N value is "the number of digits displayed to the right of the decimal point."

The 20b displays 0.01.

---

While the HP-30b does not seem to meet its specification, neither the HP-20b nor HP-30b handle this as did the "old school" HP's for FIX n:

The scientific models would revert to scientific notation (SCI n) if the number was too small for FIX n to show any significant digits. The business models, however, would keep increasing the number of decimal digits (FIX n+1) until one significant digit could be displayed, then use SCI n only if necessary.

FIX display on business vs. scientific

These display formats seem to have been tailored to the likely users of the respective models.

-- KS

Edited: 1 Dec 2010, 1:06 a.m.

[Martin Pinckney]

Why RPN, particularly? Any calculator should yield 0.01 answer to the stated example, in FIX 2 mode.

[Mark Harman]

It does it in chain and algebraic modes, also.

Mark