> When they do it's often a mistake, like for currency.

The most beautiful FP bug I remember was a denial of service in some webservers where by setting the header "Accepted Language: en-gb;q=0.3 en;q=0.8 ..." to a specific value you could send the official Java floating-point parser in an infinite loop (and this affected several Java webservers).

So at each webpage request, you were sending one CPU core of the webserver basically busy-looping. Hence crashing the webserver in a few requests at most.

Now it'd be heresy if I were to say that maybe, just maybe, had the standards mandated to use 0 to 100 for weighting instead of 0 to 1.0 we could have dodged a whole source of potential issues!?

No, no, I realize this is heresy: let's all keep using numbers that cannot even be represented correctly (except as strings), parse those strings into something approximately representing what's written in the string, then make more approximation errors while doing computation with these numbers, propagation errors, epsilon estimation errors, and keep insisting we all could have authored "What every computer scientist should known about floating-point numbers" (which is 80 pages long and, well, approaching a treaty) ; )

/rant off