REQUEST: Significant Digit Calculator

[Tim Wessman]

(01-21-2018 09:39 PM)Lavaloon Wrote:  Addition/subtraction:
2.345+8.5=10.5, an answer is rounded to least number of decimal places
7.93-4.6729=3.26, same as above

Isn't the point here that the last digit is the one that contains the "error"? Wouldn't that mean that your answer is only valid to +/-1 on the last of 2 digits? You've specified 3 digits in your "correct" answer.

This type of thing in my experience is a "good idea", but in practice has been implemented wrong. The system simply assumes your numbers are correct up to the last digit in all case. In reality, the user needs to be able to specify where the error is (some numbers won't have uncertainty, or varying levels of uncertainty) and the amount of the error. Thus these become a simple "black box" thing that doesn't actually aid understanding or be useful.

The better solution is to enable interval math, and that is something we have on the long term goals...