07-25-2001, 03:55 PM
I just got an HP15C at a yard sale as my first RPN calculator. I have no problem with most operations in RPN. However, I cant seem to find an easy way to enter negative numbers. On all my previous scientific calculators I had a +/- key that would change the sign of the value on the display. The best way I have found with the 15C is to multuply by -1, or subtract the value from zero. Is there any thing like the +/- key on the 15C? I cant see it, and I dont have a manuel.
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Thanks
E. Engwall