New Casio CWs: antilogs and scientific notation

[nlj]

Conspicuously absent from the keyboard of Casio's new CW calculators (such as the fx-991CW) are the common and natural antilogarithms. These machines are possibly the only scientific calculators I have ever seen without these functions on their keyboards.

Are the missing antilog functions available in the CATALOG menu, or are they completely absent from the calculator? (If they are in the catalog, how many key presses are required to reach them there?)

I'm guessing that Casio's idea is for one to calculate these functions explicitly? For example, does one enter e^1.23 as [SHIFT][8](e)[^][1][.][2][3][=] and 10^1.23 as [1][0][^][1][.][2][3][=]?

That's only one more keystroke in each case than using the (shifted) antilog functions on the fx-991EX keyboard. One more keystroke isn't in itself the end of the world -- except that entering the functions this way breaks one's train of thought, forcing one to think in terms of exponents when all one really wants is an inverse log.

Interestingly, on Page 33 of the CW manual[1], where it discusses entering numbers in scientific/exponential/standard notation using what it calls the "Power of 10" key, it says "Pressing the [×10^] key is the same as pressing [×][1][0][^]". Can someone with one of these calculators confirm that this surprising statement is true? [On earlier Casio calculators, providing a non-integer exponent to [×10^] is an error.]

It would certainly be an interesting twist if calculating a natural antilog on the CW requires one more keypress than on the EX (eight rather than seven in the example above), but a common antilog can be done with one fewer (six rather than seven).

Notes:
1. Casio fx-570CW and fx-991CW User's Guide https://www.casio.com/content/dam/casio/...1CW_EN.pdf

[Dave Britten]

Page 50 of the manual shows how to do a common log, but I'm not seeing mention of antilog/10^x. Rather curious omission...

[lrdheat]

If I press the shifted log key on keyboard and type in 20 then exe, I get 1.3+. If I then type 1, then *10^, then ans key, 1 get 20 back.

If I press shifted ln key on keyboard and type in 20, I get 2.99+. If I then type shifted e, then the number raised to a power key, then answer, I get 20 back.

[EdS2]

It's arguably quite neat - the firmware must be smart enough to treat e as a special case - it's almost certainly already using ln and e^x internally to perform the power function.

I notice the manual tells us that 23 digit versions of pi and e are used internally - the sort of thing that can be done with a symbolic interface.

[nlj]

(04-06-2023 04:28 PM)lrdheat Wrote:  If I press the shifted log key on keyboard and type in 20 then exe, I get 1.3+. If I then type 1, then *10^, then ans key, 1 get 20 back.

So it's true that the [×10^] key doesn't require an integer argument! Extraordinary! I'm a bit too shocked to decide if I think that's a good or a bad thing, but it's certainly interesting.

Question: Can you omit the 1? That is, instead of

Code:

[SHIFT][^2](log)[2][0][EXE]
[1][×10^][Ans][EXE]

, can you type

Code:

[SHIFT][^2](log)[2][0][EXE]
[×10^][Ans][EXE]

?

(04-06-2023 04:28 PM)lrdheat Wrote:  If I press shifted ln key on keyboard and type in 20, I get 2.99+. If I then type shifted e, then the number raised to a power key, then answer, I get 20 back.

That at least, is what one would expect, I think.

[lrdheat]

It needs the 1 before the *10^number, in this case answer. For other purposes, one could enter some other number before the *10^number key…

[Eddie W. Shore]

Yes the *10^ must have a number before it, unless an error key occurs.

I think they have removed the exp and antilog functions altogether; kind of an unexpected choice.