# How is this 7? **URL:** \ **Category:** Factual Questions\ **Created:** [August 22, 2016, 1:40am UTC](https://boards.straightdope.com/t/how-is-this-7/763594 "2016-08-22T01:40:44Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [August 22, 2016, 1:40am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/1 "2016-08-22T01:40:44Z")
[Nerd maths watch](http://www.zazzle.com/funny_math_equation_geek_wristwatches-256354630441873936) three vertical lines with a sub script 2 means what? ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [August 22, 2016, 1:43am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/2 "2016-08-22T01:43:14Z")
111 in binary is 7 base 10. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [August 22, 2016, 1:44am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/3 "2016-08-22T01:44:17Z")
I’ve just worked out my stupidity but will leave the question for your amusement. Its not vertical lines. It’s 111 in binary. Too late. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 22, 2016, 1:44am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/4 "2016-08-22T01:44:57Z")
111 in base two ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 22, 2016, 1:50am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/5 "2016-08-22T01:50:48Z")
> [@Bill\_Door](#): > > 111 in binary is 7 base 10. Nitpick: Among common number bases, it’s also 7 in octal and hexadecimal. 🙂 ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 22, 2016, 2:12am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/6 "2016-08-22T02:12:30Z")
Counter nitpick: 111 in hex is 256+16+1 = 273 decimal. 111 in octal is 64+8+1 = 73 decimal. But I get the joke. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [August 22, 2016, 3:38am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/7 "2016-08-22T03:38:23Z")
Why do computer scientists confuse Halloween with Christmas? Because OCT 31 = DEC 25! (That is, 31 in octal (base eight) is 25 in decimal (base ten).) ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 22, 2016, 3:40am UTC](https://boards.straightdope.com/t/how-is-this-7/763594/8 "2016-08-22T03:40:23Z")
> [@LSLGuy](#): > > Counter nitpick: 111 in hex is 256+16+1 = 273 decimal. 111 in octal is 64+8+1 = 73 decimal. > > But I get the joke. Counter-counter nitpick! The sentence was "111 in binary is 7 base 10. " This parses into the following constituent tree: ```auto (ROOT (S (NP (NP (CD 111)) (PP (IN in) (NP (NN binary)))) (VP (VBZ is) (NP (CD 7) (ADJP base 10))))) ``` Now my use of “it’s” – “it is” – parallels the third person singular present (VBZ) “is” in the sentence and provides additional possible values for the adjective phrase (ADJP) “base 10”, to wit, the stated octal (base 8) and hex (base 16). Therefore the noun phrase (NP) with the cardinal number (CD) 7 can equally read “7 base 10”, “7 base 8”, or “7 base 16”. This is obvious. Your move. 😃 ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [August 22, 2016, 6:31pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/9 "2016-08-22T18:31:45Z")
“This product is recommended for ages 3+” Huh? ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [August 22, 2016, 6:44pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/10 "2016-08-22T18:44:32Z")
Our product has 5x the power as theirs! ---
**Author:** ![Atamasama](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atamasama/32/12961_2.png) [@Atamasama](https://boards.straightdope.com/u/Atamasama)\ **Post date:** [August 22, 2016, 6:52pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/11 "2016-08-22T18:52:51Z")
Never mind, I blame gremlins. ---
**Author:** ![TBG](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@TBG](https://boards.straightdope.com/u/TBG)\ **Post date:** [August 22, 2016, 8:11pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/12 "2016-08-22T20:11:44Z")
There are 10 kinds of people in this thread… ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [August 22, 2016, 8:20pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/13 "2016-08-22T20:20:26Z")
Isn’t the one for 9 incorrect? Instead of 9, that watch says ```auto 3[π-.14] ``` But wouldn’t that actually come out to 9 unless they’re assuming π is 3.14, right? ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 22, 2016, 8:57pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/14 "2016-08-22T20:57:31Z")
> [@chorpler](#): > > Isn’t the one for 9 incorrect? Instead of 9, that watch says > > ```auto > > 3[π-.14] > > ``` > > But wouldn’t that actually come out to 9 unless they’re assuming π is 3.14, right? They probably should have picked a simpler math fact than rounding pi to two digits without warning. When they decided on that, they probably chose to cheat rather than have to fill up the watch face\* with a full expansion of pi to the infinitely last place. \*the watch face, and every other surface of the watch, and every surface in the entire universe… ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [August 22, 2016, 9:12pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/15 "2016-08-22T21:12:57Z")
They’re probably using the brackets to mean the [floor function](https://en.wikipedia.org/wiki/Floor_and_ceiling_functions), also called the greatest integer function. This was standard notation for floor until Iverson introduced the partial-bracket notation in the 1960s; since then Iverson’s brackets have become more common, probably because they’re less ambiguous, avoiding the confusion evident in this thread. Of course they could have just used 3[π]. –Mark ---
**Author:** ![ssgenius](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@ssgenius](https://boards.straightdope.com/u/ssgenius)\ **Post date:** [August 22, 2016, 9:15pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/16 "2016-08-22T21:15:02Z")
10mod7 and gcf(33,110) are pretty obscure as well, I had to look them both up before I understood them, although once you understand that gcf stands for greatest common factor, it is a little easier ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [August 22, 2016, 9:35pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/17 "2016-08-22T21:35:14Z")
what’s this?? **LSLGuy**? You’re back? Yippee! ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [August 22, 2016, 9:40pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/18 "2016-08-22T21:40:01Z")
> [@don\_t\_ask](#): > > I’ve just worked out my stupidity but will leave the question for your amusement. > > Its not vertical lines. It’s 111 in binary. > > Too late. I’ve done this myself before–threadshit your own OP. Please report yourself. ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [August 25, 2016, 1:00pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/19 "2016-08-25T13:00:55Z")
> [@markn\_1](#): > > They’re probably using the brackets to mean the [floor function](https://en.wikipedia.org/wiki/Floor_and_ceiling_functions), also called the greatest integer function. This was standard notation for floor until Iverson introduced the partial-bracket notation in the 1960s; since then Iverson’s brackets have become more common, probably because they’re less ambiguous, avoiding the confusion evident in this thread. Of course they could have just used 3[π]. Thank you. I’m going to choose to view it this way (even though, as you point out, that makes the whole “-.14” part unnecessary) just to keep myself from being driven mad by the thought that somebody would make a watch for “Math Geek[s]” and then commit the unpardonable sin of _assuming pi is 3.14_. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [August 25, 2016, 1:03pm UTC](https://boards.straightdope.com/t/how-is-this-7/763594/20 "2016-08-25T13:03:08Z")
> [@wolfpup](#): > > Nitpick: Among common number bases, it’s also 7 in octal and hexadecimal. 🙂 In fact, 7 is 7 in any base equal to or higher than base seven. [Next page](https://boards.straightdope.com/t/how-is-this-7/763594.md?page=2)