Google Fails 5th Grade Math Test

Calculator says... idk, 7? So, I think I finally discovered the cause of global warming. No, for reals. From what I can tell, miss Mother Nature started using Google Calculator in helping her figure out what kind of weather she should serve up to us. Now, if she were trying to bake a cake, or perhaps get driving directions, I am sure Google would have worked just fine. But for doing math involving temperatures…? Not so much.

I was playing around with the functions on Google Calculator last week, when I noticed some of the calculations weren’t quite right. Maybe Michael Bolton from Office Space was involved in writing the Google Calculator app, and wound up putting a decimal in the wrong place, but something sure isn’t adding up.

For those that don’t know, water boils at 100 degrees Celsius and freezes at 0 degrees Celsius. In Fahrenheit the range is 212 degrees (boiling) to 32 degrees (freezing). Even for those of you who might not have remembered those figures off the top of your head, most of us did learn them fairly early in our academic careers… probably right around fourth or fifth grade. While those numbers may vary slightly under extreme pressures, for the most part they are pretty much standard. A simple search on Google will in fact verify that they are correct.

Overall I think that Google Calculator is a pretty cool tool. You can even type math in using English, and it will do it’s best to figure out how to interpret the numbers. Usually it does an excellent job. When I was playing with it the other day, however, I got this odd response:


No, 64 degrees/2 does not equal a new ice age...
Erm… no.


Way off. Not even in the same ballpark. Google did manage to group the numbers in a meaningful way, correctly guessing what I actually meant by that question, and yet somehow still came up with the wrong answer. If you can’t do it in your head, that should be (64F/2) = 32F = 0C, or water’s freezing point.

Maybe it just has a problem with temperatures on the low end, I thought, and that if I go the other way we might get better results:


Hot hot hot!
Wow. That’s hot. Also wrong.


Apparently not. That one should be 106F * 2 = 212F = 100C, or the temperature at which water boils. Instead we get temperatures hotter than most home ovens can go. 😀

To give Google the benefit of the doubt, I decided to try and take out the conversions altogether, and just let it do simple temperature calculations, staying in just one measurements system:


No conversion involved, Google Calculator still gets it wrong?
Not even close. Google fails.


Nope, still no math love from the search giant. I guess Google just needs to go back to school. 😀

20 thoughts on “Google Fails 5th Grade Math Test”

  1. It may fail 5th grade math, but it just aced college chemistry. ;’) It doesn’t (usually) make sense to multiple or divide temperate in F. What it assumes you mean is “what is twice as hot as this” or “what is half as hot” when multiplying or dividing by two. So, it’s doing those operations in Kelvin for you!

    Try it: 106 degrees f in kelvin = 314.261111 kelvin
    314.261111 kelvin times two = 355.372222 degrees Celsius

    That’s where your seemingly mysterious wrong answers are coming from.

  2. Fill, that means that it is failing in a who different way, but still failing. Look at the groupings in it’s answer… it very specifically states that it is doing math in Fahrenheit or Celsius units.

    Good catch though. 🙂

  3. Hi Michael, OK let’s try doing the math without going to Kelvin and back:

    ((106 F + 459.67) * 2) – 459.67 = 355.372222 C

    Again, that gives what Google gives and notice that I had to add 459.67 before doing the multiplication and then subtracted it back out after multiplying. That’s because -459.67F is absolute zero.

    Think of it this way, say I live 10 miles from work, and for some weird reason, I decide that the coffee shop half way is ‘mile post zero’. So that would make home -5 Miles, and work 5 Miles if it were laid out on a scale. If I drove to the coffee shop, I know I’m half way so the total distance is 2 * 5 (I started at -5) NOT 2 * zero.

    The way Google is doing the math is the same way, it has an absolute zero starting point. The zero point on the F and C scales were arbitrarily picked in the same way that the coffee shop was mile zero, probably because absolute zero wasn’t known at the time or to use small enough units that are common for everyday life(?).

    BTW- This article confused me when I first read it. I started playing with Google Calculator before realizing what it was actually doing.

  4. Right, I actually understood what you meant the first time. My point is still that it is still doing invisible, unlabeled and unasked for conversions that it should not be doing, which result in it giving what is ultimately the wrong answer.

  5. Hi Michael, I was just looking at Wikipedia for giggles, and they have a good explanation and even mention the confusion with some systems like Google Calculator:

    The distinction (as we alluded to) is that degrees C can be treated as a interval (e.g. “it got 10 degrees C warmer”) vs. temperature (e.g. “it is 10 degrees C”). When doing math, it is correct to convert to Kelvin and back when dealing with temperatures. So, 2 times 10 degrees warmer is 20 degrees, but twice the temperature of 10 degrees C *is* 293.15 degrees C. This makes more sense if you had a negative temperature, say, -10 degrees C. Something twice as hot as -10 degrees C, of course, is not -20 degrees C.

    In your blog entry, I would argue that you were indeed talking about temperature and not intervals because your second to last example mentioned the result being too hot and hotter than most home ovens. So, Google would appear to be correct!

    Wikipedia’s example is adding 1 degree C to 1 degree C. It has two answers depending on if one or both are intervals (in which case the answer is 2 degrees C), but if they are both temperatures then the answer is 275.15 degrees C.

    I think the failing with Google Calculator is that it always assumes you are talking about temperature and not intervals without a way to be more explicit (as far as I know). But, I would say that when people are referring to degrees C or F that they are normally talking about temperature and not intervals.

    Thanks for the blog post! I hope I don’t come across as a dick, just found this an interesting issue that you have come across!

  6. For the people that didn’t get it, google is correct. When you say, what is twice 40 degrees celcius, it does not equal 80, it is twice the distance from absolute zero to 40 degrees c. Which is much muh bigger.

  7. The way it does it is it does this:
    what is sixty four degrees f divided by two in c=
    ((64f)/2)in celsius
    it first calculates what 64f is. if you type that into Google, you’ll get kelvin. so you get k the kelvin units.
    so it gives you k/2 in Celsius. This makes sense because 0 degrees Fahrenheit is the temperature of some sort of brine of sodium something or another and water. That is pretty darn irrelevant. So google is very smart by converting its measurements to kelvin which compares it to absolute 0. great post though

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