Summary: This is a fabulous calculator. I think it's one of the best that HP made back in the 80's. It's very well constructed and easy to use. In my case, I use it for figuring out mortgage payments and amortization schedules. I already owned an HP 18C Business Consultant calculator (which is much more expensive), but the HP 10B serves my needs quite nicely and for a fraction of the price.
Summary: Seemed like a good buy but it does not display enough decimals. Often if will cut off at 2 or three and not round up correctly. Who knows how many questions on tests ive gotten wrong because the calculator didnt carry enough decimal places through each calculation.