The Google Calculator Glitch, could float vs. double be a possible reason?
c, google-search, math
Solution
In C#, try `(double.maxvalue == (double.maxvalue - 100))`, you'll get `true` but that's what it is supposed to be.
Thinking about it, you have 64 bit representing a number greater than `2^64` (`double.maxvalue`), so inaccuracy is expected.
Problem
With Google's newfound inability to do math correctly (check it! according to Google `500,000,000,000,002 - 500,000,000,000,001 = 0`), I figured I'd try the following in C to run a little theory. ``` int main() { char* a = "399999999999999"; char* b = "399999999999998"; float da = atof(a); float db = atof(b); printf("%s - %s = %f\n", a, b, da-db); a = "500000000000002"; b = "500000000000001"; da = atof(a); db = atof(b); printf("%s - %s = %f\n", a, b, da-db); } ``` When you run this program, you get the following ``` 399999999999999 - 399999999999998 = 0.000000 500000000000002 - 500000000000001 = 0.000000 ``` It would seem like Google is using simple 32 bit floating precision (the error here), if you switch float for double in the above code, you fix the issue! Could this be it?