Wikipedia:Reference desk/Archives/Mathematics/2015 November 27

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November 27

I am trying to recall a math joke about binary numbers.

I am trying to recall a math joke. It's not so much a joke, per se. Rather, it's a witty saying that one might see on a bumper sticker or a t-shirt or such. It involves the binary notation of "0" and "1". And I think -- but am not quite sure -- that the joke revolves around the fact that the number "2" (in decimal) is written "10" (in binary). So, in other words, it appears (to the uneducated mind) that the number "10" (ten) is confusingly somehow the same thing as the number "2" (two). And the witty saying is something like this: "There are only two people in the world who understand binary." or "There are only two kinds of people in the world, those who understand binary and those who don't." or something like that. But, of course, the actual saying (that I cannot recall exactly) is actually funny and witty. Does this ring a bell with anyone? Thanks. 2602:252:D13:6D70:186C:D475:39EF:E0EC (talk) 07:00, 27 November 2015 (UTC)

WHAAOE: Mathematical joke#Jokes with numeral bases. -- BenRG (talk) 07:06, 27 November 2015 (UTC)

Repeating here for completeness: "There are only 10 types of people in the world: those who understand binary, and those who don't." -- Meni Rosenfeld (talk) 09:40, 27 November 2015 (UTC)

"Where did you learn binary numbers ?"

"In Math 101, of course." StuRat (talk) 07:33, 27 November 2015 (UTC)

There are only 3 types of people in the world: those who can count, and those who can't. Bo Jacoby (talk) 12:05, 27 November 2015 (UTC).

Once upon a time I've combined the two jokes... And it was here, on Wikipedia – see Talk:Kolmogorov complexity#Compression, just before the table.
--CiaPan (talk) 12:24, 27 November 2015 (UTC)

Thanks. Yes, that was it! This one: "There are only 10 types of people in the world: those who understand binary, and those who don't." Thanks. 2602:252:D13:6D70:A8EE:8AAC:331:7E78 (talk) 06:02, 28 November 2015 (UTC)

Thanks. 2602:252:D13:6D70:9562:88E6:981C:9C76 (talk) 06:26, 1 December 2015 (UTC)

What for inverting matrices by hand in an algebra course?

Indeed, how important is it to invert matrices at all, not only by hand? The corresponding article (Invertible matrix#Applications) has some uses of it, but often inverting can be avoided. It seems to be more of an attention exercise than actually maths. --YX-1000A (talk) 15:39, 27 November 2015 (UTC)

Have you read Don't invert that matrix? catslash (talk) 00:40, 28 November 2015 (UTC)