Rule of Thumb:

To calculate dollars "accurately" with 2 decimal places, you need
to calculate right from the beginning in cents as integers!

So just calculate with integers in the desired accuracy and shift the decimal point afterwards!

Background:

Floats are not accurate with decimal fractions because the computer "has only two fingers".

Experiment

Just try to express 1/3 accurately in decimal system!

And now imagine you're an alien with 3 fingers 4 and you have only computers that calculate in decimal fractions... wouldn't this annoy you, too?

Conclusion

Humans have too many fingers! Downsizing to octal system would do it...

Cheers Rolf

Footnotes:


In reply to Humans have too many fingers by LanX
in thread perl floating number addition by adismaug

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