I made this last night after being inspired by http://www.npr.org/templates/story/story.php?storyId=1302494... All the calculations are done with Javascript. Let me know what you think!
Trying with a value of 1e20 , 1e21 gives interesting results. More curious is that using konqueror I get one value but with firefox i get another. Seems to be some bit flipping somewhere, since with firefox I get Miscellaneous mandatory programs $16068258000000004096.00 4096, 16384 , etc but with konqueror i get: Miscellaneous mandatory programs $16068258000000005000.00 Maybe some bug with the javascript interpreter…
browser differences aside, javascript represents all numbers as floats, so as you attempt to store larger and larger numbers, you will find yourself with less and less accurate data.
i'd bet that some minor difference in order of operations between the JS implementations of FF and konqueror result in the differences you're observing.