# 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:** 4
**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\ **Post date:** [October 28, 2008, 5:05pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/61 "2008-10-28T17:05:25Z")
I had seen this one a long time ago, and when I started in on it, I thought to myself, “This is one of those that goes to the next 100 and not the next 1000.” Then, I worked through it, and thought, “4,090 + 10 = 5,000.” :smack: ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [October 28, 2008, 5:05pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/62 "2008-10-28T17:05:44Z")
> [@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? 1. ---
**Author:** ![Lavender\_Falcon](https://avatars.discourse-cdn.com/v4/letter/l/b782af/32.png) [@Lavender\_Falcon](https://boards.straightdope.com/u/Lavender_Falcon)\ **Post date:** [October 28, 2008, 5:14pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/63 "2008-10-28T17:14:30Z")
4100 ---
**Author:** ![NinetyWt](https://avatars.discourse-cdn.com/v4/letter/n/cc9497/32.png) [@NinetyWt](https://boards.straightdope.com/u/NinetyWt)\ **Post date:** [October 28, 2008, 5:24pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/64 "2008-10-28T17:24:00Z")
1. ---
**Author:** ![SpectBrain](https://avatars.discourse-cdn.com/v4/letter/s/a87d85/32.png) [@SpectBrain](https://boards.straightdope.com/u/SpectBrain)\ **Post date:** [October 28, 2008, 5:28pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/65 "2008-10-28T17:28:01Z")
4100 ---
**Author:** ![kasuo](https://avatars.discourse-cdn.com/v4/letter/k/8c91f0/32.png) [@kasuo](https://boards.straightdope.com/u/kasuo)\ **Post date:** [October 28, 2008, 5:31pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/66 "2008-10-28T17:31:05Z")
11ty billion Okay, 4100 but like a couple people have mentioned, I almost went the “5000” route. ---
**Author:** ![poker\_in\_the\_rear](https://avatars.discourse-cdn.com/v4/letter/p/dc4da7/32.png) [@poker\_in\_the\_rear](https://boards.straightdope.com/u/poker_in_the_rear)\ **Post date:** [October 28, 2008, 5:31pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/67 "2008-10-28T17:31:30Z")
4100 ---
**Author:** ![little\_bit](https://avatars.discourse-cdn.com/v4/letter/l/258eb7/32.png) [@little\_bit](https://boards.straightdope.com/u/little_bit)\ **Post date:** [October 28, 2008, 5:32pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/68 "2008-10-28T17:32:48Z")
4100 ---
**Author:** ![onedayfishsale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/onedayfishsale/32/4398_2.png) [@onedayfishsale](https://boards.straightdope.com/u/onedayfishsale)\ **Post date:** [October 28, 2008, 5:34pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/69 "2008-10-28T17:34:21Z")
4100 ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [October 28, 2008, 5:34pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/70 "2008-10-28T17:34:59Z")
1. Without reading the rest of the thread, I’m assuming you expect people to jump from 4090 + 10 = 5000? ---
**Author:** ![EristicKallistic](https://avatars.discourse-cdn.com/v4/letter/e/85e7bf/32.png) [@EristicKallistic](https://boards.straightdope.com/u/EristicKallistic)\ **Post date:** [October 28, 2008, 5:35pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/71 "2008-10-28T17:35:13Z")
42 ---
**Author:** ![IvoryTowerDenizen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ivorytowerdenizen/32/17937_2.png) [@IvoryTowerDenizen](https://boards.straightdope.com/u/IvoryTowerDenizen)\ **Post date:** [October 28, 2008, 5:36pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/72 "2008-10-28T17:36:09Z")
4100 ETA: got it! yeah! ---
**Author:** ![drillrod](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@drillrod](https://boards.straightdope.com/u/drillrod)\ **Post date:** [October 28, 2008, 5:37pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/73 "2008-10-28T17:37:21Z")
1. Crap! Am I the only honest one? ---
**Author:** ![bluecanary](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bluecanary/32/3614_2.png) [@bluecanary](https://boards.straightdope.com/u/bluecanary)\ **Post date:** [October 28, 2008, 5:39pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/74 "2008-10-28T17:39:13Z")
4100 ---
**Author:** ![PaperBlob](https://avatars.discourse-cdn.com/v4/letter/p/58956e/32.png) [@PaperBlob](https://boards.straightdope.com/u/PaperBlob)\ **Post date:** [October 28, 2008, 5:40pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/75 "2008-10-28T17:40:25Z")
4100 ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 28, 2008, 5:42pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/76 "2008-10-28T17:42:30Z")
4100 ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [October 28, 2008, 5:43pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/77 "2008-10-28T17:43:17Z")
4100, but I think they want you to say 5000 ---
**Author:** ![Freudian\_Slit](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@Freudian\_Slit](https://boards.straightdope.com/u/Freudian_Slit)\ **Post date:** [October 28, 2008, 5:44pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/78 "2008-10-28T17:44:30Z")
4,100 But I think I’d seen this one before, so I was more careful. ---
**Author:** ![Agent\_Foxtrot](https://avatars.discourse-cdn.com/v4/letter/a/9fc29f/32.png) [@Agent\_Foxtrot](https://boards.straightdope.com/u/Agent_Foxtrot)\ **Post date:** [October 28, 2008, 5:53pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/79 "2008-10-28T17:53:43Z")
I’m not sure I believe most of these 4100’s. :rolleyes: ---
**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 28, 2008, 6:06pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/80 "2008-10-28T18:06:14Z")
5,000 - I hope! eta: :smack: :smack: :smack: :smack: [Previous page](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932.md?page=3) [Next page](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932.md?page=5)