# Do this math problem in your head. **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 28, 2008, 2:08pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932 "2008-10-28T14:08:40Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Idle\_Thoughts](https://avatars.discourse-cdn.com/v4/letter/i/838e76/32.png) [@Idle\_Thoughts](https://boards.straightdope.com/u/Idle_Thoughts)\ **Post date:** [October 28, 2008, 2:53pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/21 "2008-10-28T14:53:08Z")
Now you guys know why I said no editing. 🙂 ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [October 28, 2008, 2:54pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/22 "2008-10-28T14:54:56Z")
4100, yeah? (I **have** come across it before, as a card carrying math geek, but still.) ---
**Author:** ![leafrog](https://avatars.discourse-cdn.com/v4/letter/l/cab0a1/32.png) [@leafrog](https://boards.straightdope.com/u/leafrog)\ **Post date:** [October 28, 2008, 2:57pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/23 "2008-10-28T14:57:46Z")
4100 ETA: Phew. ---
**Author:** ![Jamaika\_a\_jamaikaiake](https://avatars.discourse-cdn.com/v4/letter/j/7993a0/32.png) [@Jamaika\_a\_jamaikaiake](https://boards.straightdope.com/u/Jamaika_a_jamaikaiake)\ **Post date:** [October 28, 2008, 2:58pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/24 "2008-10-28T14:58:25Z")
4100 ---
**Author:** ![Yorikke](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yorikke/32/4335_2.png) [@Yorikke](https://boards.straightdope.com/u/Yorikke)\ **Post date:** [October 28, 2008, 3:02pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/25 "2008-10-28T15:02:35Z")
5000 ETA : Oh, I see… Joe ---
**Author:** ![Zeriel](https://avatars.discourse-cdn.com/v4/letter/z/58956e/32.png) [@Zeriel](https://boards.straightdope.com/u/Zeriel)\ **Post date:** [October 28, 2008, 3:04pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/26 "2008-10-28T15:04:02Z")
4100 I see what you did there. ---
**Author:** ![Captain\_Carrot](https://avatars.discourse-cdn.com/v4/letter/c/f0a364/32.png) [@Captain\_Carrot](https://boards.straightdope.com/u/Captain_Carrot)\ **Post date:** [October 28, 2008, 3:04pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/27 "2008-10-28T15:04:53Z")
1. ---
**Author:** ![sturmhauke](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)\ **Post date:** [October 28, 2008, 3:05pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/28 "2008-10-28T15:05:12Z")
> [@Idle\_Thoughts](#): > > Do not read any of the replies before you reply yourself with your answer. > Do not edit your reply please. > > First take 1000, then add 40 and then add 1000. Now add 30. Next add 1000 and then add 20. Then add 1000 and finally, add 10. > Sorry for the annoying way this OP is set up (with all of the spoiler boxes), but I’m curious over what answer people will get. Again, hit reply and post your answer BEFORE you read any other answers in here. > > What is the number you wind up with? 4100 ---
**Author:** ![Eureka](https://avatars.discourse-cdn.com/v4/letter/e/74df32/32.png) [@Eureka](https://boards.straightdope.com/u/Eureka)\ **Post date:** [October 28, 2008, 3:08pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/29 "2008-10-28T15:08:46Z")
4100 I think I could be susceptible to getting it wrong if it were asked of me in person rather than in print on a message board–This way I was saying numbers out loud–like “one zero four zero”, which really emphasizes which column each number goes into. In person, I might get more casual about it. ---
**Author:** ![aerodave](https://avatars.discourse-cdn.com/v4/letter/a/f08c70/32.png) [@aerodave](https://boards.straightdope.com/u/aerodave)\ **Post date:** [October 28, 2008, 3:11pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/30 "2008-10-28T15:11:34Z")
4100 ---
**Author:** ![Scarlett67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scarlett67/32/7387_2.png) [@Scarlett67](https://boards.straightdope.com/u/Scarlett67)\ **Post date:** [October 28, 2008, 3:13pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/31 "2008-10-28T15:13:20Z")
1. What do I win? ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [October 28, 2008, 3:14pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/32 "2008-10-28T15:14:22Z")
4100; I’m guessing 5000 is the expected wrong answer, since that’s what I got on the first try, but then I got suspicious as to how those tens all were supposed to add up to 1000… ---
**Author:** ![Crotalus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crotalus/32/41_2.png) [@Crotalus](https://boards.straightdope.com/u/Crotalus)\ **Post date:** [October 28, 2008, 3:14pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/33 "2008-10-28T15:14:42Z")
4100 ---
**Author:** ![Idle\_Thoughts](https://avatars.discourse-cdn.com/v4/letter/i/838e76/32.png) [@Idle\_Thoughts](https://boards.straightdope.com/u/Idle_Thoughts)\ **Post date:** [October 28, 2008, 3:16pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/34 "2008-10-28T15:16:04Z")
> [@Eureka](#): > > 4100 > > I think I could be susceptible to getting it wrong if it were asked of me in person rather than in print on a message board–This way I was saying numbers out loud–like “one zero four zero”, which really emphasizes which column each number goes into. In person, I might get more casual about it. Yeah, that’s what I meant in another post I made in here. A lot (more than you’d think) get it wrong when it’s said aloud. More than 75 percent, actually (at least of the people that I’ve done it to). It’s easier when it’s written out because then people can just add up the four 1000’s and then add up 10, 20, 30, 40 (to get 100) and then add it onto 4000. This is why I used spoiler boxes…so people would have to look at them all one at a time (and hopefully do the problem as they go along). Not too bad, either. Five, so far, were fooled. I was fooled the first time I heard it too, by the way (which was it being said aloud to me–not seeing it written). ---
**Author:** ![The\_Understander](https://avatars.discourse-cdn.com/v4/letter/t/3da27b/32.png) [@The\_Understander](https://boards.straightdope.com/u/The_Understander)\ **Post date:** [October 28, 2008, 3:17pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/35 "2008-10-28T15:17:10Z")
Here’s what went on in my head, verbatim: “5000–wait, 4,100!” And then I was cast into the Gorge of Eternal Peril. Fortunately, I am already at work so it was a short drop. ---
**Author:** ![Qwisp](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qwisp/32/397_2.png) [@Qwisp](https://boards.straightdope.com/u/Qwisp)\ **Post date:** [October 28, 2008, 3:30pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/36 "2008-10-28T15:30:50Z")
5000 ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [October 28, 2008, 3:30pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/37 "2008-10-28T15:30:54Z")
Well, my first reaction, is _what math problem_? How am I supposed to do a problem when there’s no numbers, just commands to add. Then I realize I’m allowed to look in the spoiler boxes, just not other people’s answers. My answer-thought is “forty”-“one hundred”, which translates into “forty one”-“hundred”, or 4100. I processed it in groups of two digits, probably because when I see “1040”, I think “ten”-“forty”. And the subsequent additions didn’t require changing that. ---
**Author:** ![fachverwirrt](https://avatars.discourse-cdn.com/v4/letter/f/94ad74/32.png) [@fachverwirrt](https://boards.straightdope.com/u/fachverwirrt)\ **Post date:** [October 28, 2008, 3:34pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/38 "2008-10-28T15:34:01Z")
4100 ---
**Author:** ![Eureka](https://avatars.discourse-cdn.com/v4/letter/e/74df32/32.png) [@Eureka](https://boards.straightdope.com/u/Eureka)\ **Post date:** [October 28, 2008, 3:34pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/39 "2008-10-28T15:34:04Z")
> [@Idle\_Thoughts](#): > > This is why I used spoiler boxes…so people would have to look at them all one at a time (and hopefully do the problem as they go along). What I’m talking about has nothing to do with seeing the numbers all at once, I did each petty math problem after clicking on the spoiler box. I’m just saying that seeing the numbers made me more aware of how many zeros each had than I might have been if I’d just heard the numbers. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 28, 2008, 3:36pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/40 "2008-10-28T15:36:10Z")
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