Here’s a math problem for you. Can you figure out why in the following excel spreadsheet, the two results are different? (Click the image to enlarge)
After you’re done, here’s a good read for an example of how floating point ‘issues’ can cost a lot! : Roundoff error and the patriot missile.
I’m stumped, and I even duplicated it in Excel.. When there are more than nine numbers to the right of the decimal point, this error occurs. Otherwise the results are equal. Please enlighten me.
Excel uses the IEEE 754 (see http://en.wikipedia.org/wiki/IEEE_754) which gives rounding problems because with this standard some decimals can not be stored exactly in a binary combination (but the IEEE 754 standard is still used because intell coprocessors can very easily and quick calculate with those numbers)