I just found a #MastodonBug, which is also a bug in #Fedilab @apps (FYI): with Fedilab polls rarely sum up to 100%, and then nearly ever the same as Mastodon. This is most likely a rounding error that both do without compensating, so it's more or less a display error, but it is a bug nonetheless. Here is an example for a poll where both fail to correct the wrong sum: https://tooot.im/@EhudNagar/109513566540079507
@nadavr
That's because it is rounded one number before the comma (unity). The only solution would be to display results rounded after one or two digits after the comma.
@apps
That's not a bad solution either, even though percentages may still not sun to a round 100. Please consider the idea in the second toot.