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Full Version: Multiplication Poll: * or · or something else?
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(04-12-2014 06:44 AM)Joe Horn Wrote: [ -> ]The HP-38G, "Elsie", has a [*] key instead of a [×] key. Is that the one you're thinking of?

That is the one. The lowly HP-38G is the only calculator to get it "right".

Mark Hardman
(04-12-2014 02:03 PM)Mark Hardman Wrote: [ -> ]The lowly HP-38G is the only calculator to get it "right".

Unfortunately it has an x^y key instead of **, as real programmers know it should be. Today's bonus factoid: In Prime's CAS, ** can be used as an alias for x^y.
(04-12-2014 12:56 PM)David Hayden Wrote: [ -> ]The problem with "∙" on a key is that it can be confused with the decimal point (at least in countries that use a dot). And the problem with × (multiply sign) is that it can be confused with the letter x. So maybe * is the best choice.

Maybe it will turn out that way.

For the time being, there are at least two sets in common use:
1. Decimal point, multiplication ×, division ÷
2. Decimal comma, multiplication •, division :
And there are internationally agreed fixed symbols (hurrah!!) for additions, subtractions, for dot (scalar) products and cross products.

Maybe we should use a third set for the two common arithmetic operations: multiplication * and division / ? It's quite spread in programming languages ...
And it's clearly visually differentiable - another advantage. Just compare:
1. 1.2 + - × ÷ • ×
2. 1,2 + - • : • ×
3. + - * / • ×

d:-)
(04-12-2014 06:44 AM)Joe Horn Wrote: [ -> ]
(04-12-2014 01:48 AM)Mark Hardman Wrote: [ -> ]Interestingly, the still unnamed handheld calculator also uses the "*" for "the key".

The HP-38G, "Elsie", has a [*] key instead of a [×] key. Is that the one you're thinking of?

No wonder I was puzzled. I've never used or even held an HP-38G. But this quiz did help me to organize a portion of my collection, so thanks for that Mark.
(04-11-2014 11:08 PM)Mark Hardman Wrote: [ -> ]I have 120 HP calculators on my credenza:

All but one of them features this for the multiplication key:

×

As a diversion from the pressing issue of unimaginably incorrect "national US-American customs", can you name the model with the different multiplication key?

Mark Hardman

Beautiful collection!
(04-14-2014 01:40 PM)Eddie W. Shore Wrote: [ -> ]Beautiful collection!

Thanks! You should see her mother.

Mark Hardman
Quote:That is the one. The lowly HP-38G is the only calculator to get it "right".

....and FWIW the 38G+ also had the "*" as well.....but it was cancelled before release.

Jake

(03-07-2014 06:53 PM)Tim Wessman Wrote: [ -> ]How about a poll: Would you prefer to see ·,* or something else for multiplication in 2D display mode? What about the program editor, notes/text, or non-2D mode?

I voted for · for 2D display as the intent of that mode is to display things as you would see them in a textbook

I voted for * for the program editor as this is what nearly every programming language uses. The 1D display should be consistent with the program editor.

-wes
(04-16-2014 02:37 PM)Wes Loewer Wrote: [ -> ]
(03-07-2014 06:53 PM)Tim Wessman Wrote: [ -> ]How about a poll: Would you prefer to see ·,* or something else for multiplication in 2D display mode? What about the program editor, notes/text, or non-2D mode?

I voted for · for 2D display as the intent of that mode is to display things as you would see them in a textbook

I voted for * for the program editor as this is what nearly every programming language uses. The 1D display should be consistent with the program editor.

(2 hours later)
On second thought...

I teach in Kenya at an American curriculum high school. American elementary school textbooks generally use × for multiplication till around grade 6 or 7. When the concept of variables are introduced, they switch to using a dot to avoid confusion with the variable x. We would definitely not use × in Algebra or beyond.

That said, one of my top students several years ago initially failed our math entrance exam because she didn't know what the multiplication dot meant. She was an 11th grader coming from a British curriculum school in Tanzania and had never seen it before. I've heard the same thing from other British/Kenyan students. I've seen some Kenyan textbooks use the center dot for the decimal place (3·14159).

I've always thought the * looked so out of place in the Prime's 2D display. To my American eyes, it ought to be a dot. I'm curious if the centered dot is still used as a decimal point in schools in the UK. If it is, then I would qualify my vote by saying that I'd prefer the dot, but for the sake of others, the dot should be used only if it's optional.

See http://en.wikipedia.org/wiki/Interpunct#British_English

Calculator survey:
* TI-84+, HP-50g 1D
· TI-Nspire, HP-50g 2D
× Casio

-wes
I know this thread is old, but I saw it only today searching for something else.

The SI (the international system of units) defines as the only accepted symbol for the multiplication between two numbers the cross. See the complete SI brochure on page 134 (english) or 45 (french).

I really don't see why we should use something different if it is already internationally defined.
The NumWorks calculator is conducting the same survey to implement the multiplication symbol, according to the results of the same

https://workshop.numworks.com/surveys/si...iplication

The formal mathematical language, the symbol of multiplication is an intermediate point (·) or the symbol (+) rotated 45 ° (× ASCII # 215), both (·) and (×) it is only written to give clarity in a definition, but not in everyday use. Although the symbol (×) should be better used best for the Cartesian product or cross product
To give taste to several input styles, calculators and mathematical packages have to allow the interpretation of asterism (*), as well as the intermediate point (·) as multiplication symbols

84/6·x + 84/12·x + 84/7·x + 5·84 + 84/2·x + 4·84 = 84·x
84/6*x + 84/12*x + 84/7*x + 5*84 + 84/2*x + 4*84 = 84*x
84/6×x + 84/12×x + 84/7×x + 5×84 + 84/2×x + 4×84 = 84×x

But they have to show by default only the intermediate point in the output (·), since it occupies less horizontal space and the mathematical expression is more readable
The survey should also ask about the use of the standard symbol ÷ as a division operator as linear input (Algebraic mode)

84÷6·x + 84÷12·x + 84÷7·x + 5·84 + 84÷2·x + 4·84 = 84·x
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