HP's earliest financial calculators do not have an EEX key, so it would appear that entering large numbers such as 10 billion might be rather awkward. However, when playing around with my HP-22 I accidentally stumbled on something when I entered too many zeros. If I enter a large number that goes to more than 10 places, it automatically goes into scientific notation and the exponent keeps rising with each additional digit entered. Whereas on an HP-35 I would enter EEX 10 for ten billion, on the HP-80 I would key in 1 followed by 10 zeros. I can find no mention of this in the HP-22 manual.

Now, when I look at the manuals for the two financials that preceded the HP-22, the HP-80 and HP-70, they do mention that you key in large numbers this way.

I wonder if anyone else who owns an HP-80, HP-70 or HP-22 has noticed this feature?

(05-29-2017 09:21 PM)bshoring Wrote: [ -> ]I wonder if anyone else who owns an HP-80, HP-70 or HP-22 has noticed this feature?

I have noticed this feature and think this is a brilliant idea. However it is somewhat difficult to enter 1 E 99

Yet financial calculators are not meant to be used by astronomers.

(05-29-2017 09:21 PM)bshoring Wrote: [ -> ]HP's earliest financial calculators do not have an EEX key, so it would appear that entering large numbers such as 10 billion might be rather awkward. However, when playing around with my HP-22 I accidentally stumbled on something when I entered too many zeros. If I enter a large number that goes to more than 10 places, it automatically goes into scientific notation and the exponent keeps rising with each additional digit entered. Whereas on an HP-35 I would enter EEX 10 for ten billion, on the HP-80 I would key in 1 followed by 10 zeros. I can find no mention of this in the HP-22 manual.

Now, when I look at the manuals for the two financials that preceded the HP-22, the HP-80 and HP-70, they do mention that you key in large numbers this way.

I wonder if anyone else who owns an HP-80, HP-70 or HP-22 has noticed this feature?

I think this is because the calculators do not have the EEX key so it creates a way of entering a large number. It appears that you cannot enter a negative exponent in this way.

Page 13 of the HP80 manual mentions this.

I suppose for a financial calculator, you want big $ numbers not small ones :-)

cheers

Tony

No, it appears that you cannot enter really small numbers this way.

The funny thing is that when I got an HP-80, I skipped over the part in the manual about number entry, as I figured "I knew all that." It just goes to show that you can't always make that assumption.

It's interesting that this is *not* in the manual. I discovered it in the past probably by just playing with the machine (though it may have been discovered on an HP-80 as I owned that first) but, like you, probably skipped the 'number entry' section when working through the manual.

You can easily achieve the entry of very small numbers using a variation of this same technique as follows:

Enter 10000000000... until you get to the positive magnitude of the negative exponent you want

[ENTER]

1

[X<>Y]

[/]

Mantissa

[X]

So, to get 4.556 E-15, do

1000000000000000 (that's 15 zeros)

[ENTER]

1

[X<>Y]

[/]

4.556

[X]

You lose the T register, but otherwise it gets it done.

These days, it seems the very large numbers are needed by financial folks dealing with National Debt issues, but the very smallest numbers only when dealing with effective interest rates earned at your local bank.

This makes one wonder how many other features we all 'know' aren't in the manuals at all.

(05-29-2017 09:21 PM)bshoring Wrote: [ -> ]Now, when I look at the manuals for the two financials that preceded the HP-22, the HP-80 and HP-70, they do mention that you key in large numbers this way.

Very interesting! Thanks for sharing this.

Are there any other calculators besides the HP-22, HP-70 and HP-80 supporting this input method (perhaps even some featuring an EEX button as well)?

By your description I take it that this works for digits other than zero as well?

Greetings,

Matthias

It works with all digits.

(05-29-2017 11:11 PM)matthiaspaul Wrote: [ -> ]Very interesting! Thanks for sharing this.

Are there any other calculators besides the HP-22, HP-70 and HP-80 supporting this input method (perhaps even some featuring an EEX button as well)?

By your description I take it that this works for digits other than zero as well?

Greetings,

Matthias

The HP-9815 supports this input method AND features an EEX button. Best of both world.

François

This is interesting as I was working on the "scientific notation" article in Wikipedia recently (which does not cover this implied input method so far). Brings up a number of questions (regardless of brand):

- First calculator to support number display in scientific notation (with or without a dedicated mode)?

- First pocket calculator to support number display in scientific notation (with or without a dedicated mode)?

- First calculator to support some kind of "enter exponent" key?

- First pocket calculator to support such key? (HP-35 in 1972?)

- Origin of the E-notation (like in -1.23E-45)? (The first occurance I could find so far was in FORTRAN II as of 1958, but the notation might be even older.)

Greetings,

Matthias

(05-29-2017 11:11 PM)matthiaspaul Wrote: [ -> ] (05-29-2017 09:21 PM)bshoring Wrote: [ -> ]Now, when I look at the manuals for the two financials that preceded the HP-22, the HP-80 and HP-70, they do mention that you key in large numbers this way.

Very interesting! Thanks for sharing this.

Are there any other calculators besides the HP-22, HP-70 and HP-80 supporting this input method (perhaps even some featuring an EEX button as well)?

By your description I take it that this works for digits other than zero as well?

Greetings,

Matthias

I can confirm that hp30b does not.

I wonder if it is possible to reverse from scientific notation back to "standard" notation. I suppose that in contability you need to know all the digits in a certain number, an approximation with two, three or four significant digits in scientific notation is not enough.