Why is it that only one significant figure for any uncertainty is taught? It seems like a nice general rule, but isn't it an unnecessary constraint and ultimately a poor rule in many cases? For example ## 5 \pm 1 ## could mean an error of either 0.5 or 1.5, which is a very large range. Wouldn't it be best to keep an additional significant figure in this case? If not, could you possibly expand on why? I have also seen more than one significant figure widely reported in research, and it doesn't seem to be too problematic in publications, yet I see this commonly taught at the high school and undergraduate level. Any advice would be great!