# 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:** 8
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [October 29, 2008, 3:11pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/141 "2008-10-29T15:11:11Z")
Highlighting the spoiler boxes one at a time was the problem. My brain would have grouped the 1,000s and the 10s separately in real life. At least that’s my story, and I’m sticking to it. 😉 ---
**Author:** ![Alive\_At\_Both\_Ends](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@Alive\_At\_Both\_Ends](https://boards.straightdope.com/u/Alive_At_Both_Ends)\ **Post date:** [October 29, 2008, 3:34pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/142 "2008-10-29T15:34:21Z")
1. ---
**Author:** ![pravnik](https://avatars.discourse-cdn.com/v4/letter/p/8edcca/32.png) [@pravnik](https://boards.straightdope.com/u/pravnik)\ **Post date:** [October 29, 2008, 4:07pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/143 "2008-10-29T16:07:35Z")
> [@Idle\_Thoughts](#): > > I just realized something. > > When you put the mouse over the topic, you get a preview and the spoilers tags don’t show. > > In my opinion, this makes it much easier to get the right answer…because (like I said before) people see ALL of the numbers in one place, so they’re apt to just add together all of the 1000s first (getting 4000) and then add the 10, 20, 30, 40 together (getting 100) and then just add 4000 and 100. > > Go on, admit it if you did that. 🙂 I did that _and I still got 5000_. The whole time I was going “Okay, I got five thousand, but I know it’s a trick, add it again…five thousand again. I don’t get it, what’s the trick? Screw it, I’m looking at the answer…Oh.” :smack: ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [October 29, 2008, 4:28pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/144 "2008-10-29T16:28:49Z")
1. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [October 29, 2008, 4:35pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/145 "2008-10-29T16:35:56Z")
> [@cmyk](#): > > **8,963.2777[…]** You know, there’s a patch for those early Pentiums. ---
**Author:** ![Wargamer](https://avatars.discourse-cdn.com/v4/letter/w/df705f/32.png) [@Wargamer](https://boards.straightdope.com/u/Wargamer)\ **Post date:** [October 29, 2008, 5:04pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/146 "2008-10-29T17:04:07Z")
4100 ---
**Author:** ![Caveat\_lector\_1](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@Caveat\_lector\_1](https://boards.straightdope.com/u/Caveat_lector_1)\ **Post date:** [October 29, 2008, 5:39pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/147 "2008-10-29T17:39:00Z")
4100 ---
**Author:** ![Trepa\_Mayfield](https://avatars.discourse-cdn.com/v4/letter/t/edb3f5/32.png) [@Trepa\_Mayfield](https://boards.straightdope.com/u/Trepa_Mayfield)\ **Post date:** [October 29, 2008, 5:46pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/148 "2008-10-29T17:46:24Z")
Chestnuts, chestnuts. 1. ---
**Author:** ![Sanity\_Challenged](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@Sanity\_Challenged](https://boards.straightdope.com/u/Sanity_Challenged)\ **Post date:** [October 29, 2008, 5:55pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/149 "2008-10-29T17:55:24Z")
1. ok, 4100 ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [October 29, 2008, 5:56pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/150 "2008-10-29T17:56:46Z")
4100 ---
**Author:** ![Risha](https://avatars.discourse-cdn.com/v4/letter/r/5fc32e/32.png) [@Risha](https://boards.straightdope.com/u/Risha)\ **Post date:** [October 29, 2008, 6:24pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/151 "2008-10-29T18:24:22Z")
1. ---
**Author:** ![Risha](https://avatars.discourse-cdn.com/v4/letter/r/5fc32e/32.png) [@Risha](https://boards.straightdope.com/u/Risha)\ **Post date:** [October 29, 2008, 6:48pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/152 "2008-10-29T18:48:14Z")
I’m glad to see that I didn’t fall for it. I know that I did the first time I heard it, though, several years ago. ---
**Author:** ![masterofnone](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@masterofnone](https://boards.straightdope.com/u/masterofnone)\ **Post date:** [October 29, 2008, 7:00pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/153 "2008-10-29T19:00:08Z")
4100 ---
**Author:** ![hende](https://avatars.discourse-cdn.com/v4/letter/h/aca169/32.png) [@hende](https://boards.straightdope.com/u/hende)\ **Post date:** [October 29, 2008, 7:00pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/154 "2008-10-29T19:00:21Z")
4100… but I can see people answering 5000 ---
**Author:** ![Justin\_Credible](https://avatars.discourse-cdn.com/v4/letter/j/a8b319/32.png) [@Justin\_Credible](https://boards.straightdope.com/u/Justin_Credible)\ **Post date:** [October 29, 2008, 7:26pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/155 "2008-10-29T19:26:07Z")
1. Is there something I’m missing? ---
**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 29, 2008, 7:27pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/156 "2008-10-29T19:27:56Z")
> [@Justin\_Credible](#): > > 1. Is there something I’m missing? Yes. That Wednesday in 3rd grade when they taught addition. ---
**Author:** ![maladroit](https://avatars.discourse-cdn.com/v4/letter/m/f475e1/32.png) [@maladroit](https://boards.straightdope.com/u/maladroit)\ **Post date:** [October 29, 2008, 7:31pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/157 "2008-10-29T19:31:06Z")
4100 ---
**Author:** ![Justin\_Credible](https://avatars.discourse-cdn.com/v4/letter/j/a8b319/32.png) [@Justin\_Credible](https://boards.straightdope.com/u/Justin_Credible)\ **Post date:** [October 29, 2008, 7:31pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/158 "2008-10-29T19:31:17Z")
Okay, I got 4100 the second time. I have no idea why I got 5k the first. ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [October 29, 2008, 7:32pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/159 "2008-10-29T19:32:32Z")
First try and no double-checking: 5000 DOH! That’s why I use a computer or calculator instead of trusing my brane. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 29, 2008, 7:44pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/160 "2008-10-29T19:44:37Z")
4100 [Previous page](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932.md?page=7) [Next page](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932.md?page=9)