Clearing a mistake entry...

[Joe]

OK. Just got my first HP, a 12C. I've used HP's before however, I have never owned one of my own. I've read the page here that gives a primer on RPN. The part about the registers is very interesting.

My question: suppose you want to add two numbers. You do the following:
5
ENTER
3 - oops, that should have been a 2. So how do you do you 'clear' the 3 and enter a 2? I've been hitting 'clx', the response is correct, but is there a better way?

thanks,
joe

[Vieira, Luiz C. (Brazil)]

Hi;

in the HP12C this is the only way to replace the number in the X-register for a 0.00 and write something else over it. Ohter models have a back-space, or right-arrow, or [<-] key so you can delete last entered digit instead of the complete number. The HP12C and most vintage models do not have it (I think the HP41 was the first HP calculator with the back-space resource...)

Also, you can simply roll the stack contents down, say:

INPUT  PRESS   DISPLAY

5     [ENTER]  5.00

3      [Rv]    5.00

2      [+]     7.00

In this case, wrong entry is lost when new number in input. And use [x<>y], too. In this case, the wrong entry is not lost, instead it goes to the Y-register.

INPUT  PRESS   DISPLAY

5     [ENTER]  5.00

3     [x<>y]   5.00

2      [+]     7.00

Hope this helps.

Best regards - Luiz C. Vierb - Brazil

[Joe]

Thank you Luiz.

joe