# Math textbook stupidity **URL:** \ **Category:** Factual Questions\ **Created:** [December 16, 2004, 5:29pm UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179 "2004-12-16T17:29:03Z")\ **Posts on this page:** 6\ **Page:** 3
**Author:** ![Martin\_Hyde](https://avatars.discourse-cdn.com/v4/letter/m/47e85d/32.png) [@Martin\_Hyde](https://boards.straightdope.com/u/Martin_Hyde)\ **Post date:** [January 1, 2005, 11:19pm UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/41 "2005-01-01T23:19:01Z")
> [@Inigo Montoya](#): > > I know Montana is right next to Canada, but its still in the US, right? Why is a 'merkin textbook discussing Celcius? That’d be my answer. > > -5 x 4 is -20 The publisher was probably just thinking “how many points away from zero is that?” > > Yeah, the relative energy involved is not the same thing…let’s just hope the same kind of assumptions are not made in Biology class. Probably because American schools from K-12 through university level make use of many metric measurements all the time, so a familiarity with them only makes educational sense. ---
**Author:** ![robcaro](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@robcaro](https://boards.straightdope.com/u/robcaro)\ **Post date:** [January 1, 2005, 11:30pm UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/42 "2005-01-01T23:30:18Z")
> [@robcaro](#): > > And what was your answer? My calculator says that the answer is 4. :smack: Damn poor calculator that doesn’t know an uncalculable problem. I stand corrected. :smack: ---
**Author:** ![El\_Zagna](https://avatars.discourse-cdn.com/v4/letter/e/d2c977/32.png) [@El\_Zagna](https://boards.straightdope.com/u/El_Zagna)\ **Post date:** [January 2, 2005, 4:02am UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/43 "2005-01-02T04:02:50Z")
It has to do with the different types of numbers. From my statistician days I remember that there were nominal, ordinal, natural and cardinal (other categories are out there also). This is important to statisticians because it determines what kind of tests you can run on the data. Nominal numbers are just numbers that are used as a name. In databases you might use 1 = Alabama, 2 = Alaska. 3 = Arkansas. You can’t do any arithmetic operations an nominal numbers, e.g., 2+3 != Florida. Ordinal numbers show the order of something. In statistics you often group people’s income by ordinal numbers, e.g., 1 = $0 - $5,000, 2 = $5,000 - $10,000, etc. You know from the number whether one preson’s income is greater than another’s, but you can’t say by how much other than crude estimate. Natural numbers, which is what temperatures are, can be added and subtracted but not multiplied or divided because there is no true zero. Zero degrees Celcius or Farenheit are arbitrary points on the thermometer. Even if you look at the Kelvin scale, I don’t think you can say that 100 K is twice as hot as 50 K. Finally cardinal numbers (distance between point A and point B, weight, etc) can be added, subtracted, multiplied and divided. [This page](http://www.edu-orchard.net/PROFESS/LESSON/MATH/MATH46/ma46fjbl.html) has a lesson plan on this that appears to be directed at 4th - 6th graders. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [January 2, 2005, 4:43am UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/44 "2005-01-02T04:43:27Z")
Good explanation, **bnorton** , although FWIW the Stats textbook I’ve taught from calls 'em **nominal** , **ordinal** , **interval** , and **ratio** scales or levels of measurement. (The terms “natural numbers” and “cardinal numbers” are used to mean something different in math.) ---
**Author:** ![Kaitlyn](https://avatars.discourse-cdn.com/v4/letter/k/73ab20/32.png) [@Kaitlyn](https://boards.straightdope.com/u/Kaitlyn)\ **Post date:** [January 2, 2005, 11:07am UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/45 "2005-01-02T11:07:05Z")
> [@Scarlett67](#): > > Occasional math textbook copyeditor checking in. > > I wish I had a buck for every time I’ve asked authors to correct this error. Bill Walsh ([http://www.theslot.com](http://www.theslot.com)) has an excellent explanation of why “X times less/shorter/smaller” is a meaningless entity. “One time smaller” than anything is zero; any larger numbers are meaningless in this context. I always ask the author to change it to “one-fifth as large” or whatever it is that they REALLY mean. > > As for the “times colder” issue; as others have said, cold is an absence of heat. There is no such thing as an amount of cold. Even in Kelvin. > > And while I’m ranting, here’s one I corrected a few times just today: “Four times larger” is actually FIVE times AS MUCH. Think about it. “One time larger” would be double, no? And things progress from there. > > Innumeracy thrives. I have been ranting incoherently about both of these, which frequently occur in the media, for years and nothing has been done about it. I suppose it would help if I ranted at someone other than my wife, who has little power to actually change the situation, but you use whatever target is available, I suppose. ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [January 2, 2005, 5:14pm UTC](https://boards.straightdope.com/t/math-textbook-stupidity/280179/46 "2005-01-02T17:14:06Z")
Update that I’d forgotten to post for a while: remember that Monday or Tuesday that there was a huge cold snap a bit before Christmas? Dan Rather led off the news that night with, “Across a third of the nation, temperatures were half of what they were yesterday.” [Previous page](https://boards.straightdope.com/t/math-textbook-stupidity/280179.md?page=2)