A number with error becomes an interval:

10° ± 0.5° becomes [9.5, 10.5]°.

You can sum these intervals just as you add numbers:

+

=

If you have found a bug, please report it at the Codeberg project page.

If you have a suggestion or a question, please write Oleksandr Kaleniuk, Ph. D., Senior lecturer at DTE / IATE / ISKPI.