As many of you, I use Google to manage my web searching and this brings me to use it for other activities too. Like I use it for a calculator and I find it way easier than using an actual calculator - I don't really have many space on my desk, plus I am constantly using Google to search stuff and calculate more complicated numeric expressions than my calculator is capable of crunching.

But today I have noticed something, that really makes me part with my trust in Google Calculator. Please check the following calculation, conducted in Ecosia, Bing, DuckDuckGo and Google:

Bing calculation for 2400-2399.9998 gives us the actual result of 0.0002.

DuckDuckGo calculation for 2400-2399.9998 gives us the actual result of 0.0002 too.

Ecosia calculation for 2400-2399.9998 is no doubt correct in the result of 0.0002.

Lo and behold for the surprise that the top search engine of the World, the company, that tames the Great Network brought us - Google calculation for 2400-2399.9998 is equal to 0.00019999999.

OK, many of you will think "That is not the biggest issue of our time, why should I care?" and probably it is not a great deal, that I ask this, but I really calculate numeric values for tangent inverses and some more complicated stuff. I wonder into what extend does this little Google-bug leads to errors when it calculates functions described by complicated Taylor expressions for example.

So my question is finally clear to ask and I hope to have somebody here, who can answer it: Am I supposed to stop using Google Calculator to result my trigonometric, hyperbolic, irrational, transcendental numeric expressions?

  • Thank you @Glorfindel for your remarks regarding the way I expressed my question. Your advice will be of good use for the next time I ask about something here. – ecclesiastes May 5 at 10:01
  • good find. interestingly, bug is not present at 2-decimal subtraction 2400-2399.98 then starts at 3-decimal subtraction 2400-2399.998 and it holds until 6-decimal subtraction 2400-2399.999998 which is correct again – user0 May 5 at 10:05
  • Not only, @user0. When you keep adding 9, the behavior repeats - sometimes it prints 2.0008883e-*SomeDegree*, and sometimes it is like 1.99997885e-*SomeDegree*. Interestingly, the other search engines that I have mentioned above calculate precisely. Hm... – ecclesiastes May 5 at 10:12

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