# Do this math problem in your head. **URL:** https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932 **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:** 1
### 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, 2:08pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/1 "2008-10-28T14:08:40Z")
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? ---
### Author: ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles) #### Post date: [October 28, 2008, 2:10pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/2 "2008-10-28T14:10:07Z")
4100 ---
### Author: ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger) #### Post date: [October 28, 2008, 2:10pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/3 "2008-10-28T14:10:25Z")
4100 ---
### Author: ![ivan\_astikov](https://avatars.discourse-cdn.com/v4/letter/i/58f4c7/32.png) [@ivan\_astikov](https://boards.straightdope.com/u/ivan_astikov) #### Post date: [October 28, 2008, 2:11pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/4 "2008-10-28T14:11:12Z")
5000. Do I win anything for being first?\*\*\*\*\* \*\*\*\*\*No, because you came third. And got it wrong! ---
### Author: ![Fuzzy\_Dunlop](https://avatars.discourse-cdn.com/v4/letter/f/848f3c/32.png) [@Fuzzy\_Dunlop](https://boards.straightdope.com/u/Fuzzy_Dunlop) #### Post date: [October 28, 2008, 2:12pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/5 "2008-10-28T14:12:07Z")
> [@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? 4,100 ---
### Author: ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter) #### Post date: [October 28, 2008, 2:12pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/6 "2008-10-28T14:12:30Z")
1. ---
### Author: ![Petrobey\_Mavromihalis](https://avatars.discourse-cdn.com/v4/letter/p/bcef8e/32.png) [@Petrobey\_Mavromihalis](https://boards.straightdope.com/u/Petrobey_Mavromihalis) #### Post date: [October 28, 2008, 2:18pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/7 "2008-10-28T14:18:53Z")
1. I’m going to look stupid, aren’t I? Why, yes I am. I see how it works now. Ah, well. Will you believe if I say I’ve actually got quite a high IQ? Thought not. ---
### 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, 2:20pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/8 "2008-10-28T14:20:06Z")
> [@Petrobey\_Mavromihalis](#): > > 1. > > I’m going to look stupid, aren’t I? Probably..but you’re not the only one. 🙂 ---
### Author: ![Dunderman](https://avatars.discourse-cdn.com/v4/letter/d/ecb155/32.png) [@Dunderman](https://boards.straightdope.com/u/Dunderman) #### Post date: [October 28, 2008, 2:20pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/9 "2008-10-28T14:20:45Z")
1. ---
### Author: ![Annie-Xmas](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@Annie-Xmas](https://boards.straightdope.com/u/Annie-Xmas) #### Post date: [October 28, 2008, 2:20pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/10 "2008-10-28T14:20:49Z")
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, 2:22pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/11 "2008-10-28T14:22:07Z")
This works a lot better if you say it aloud to someone. When I say it aloud to people, hardly anyone gets it right. Maybe one in ten do (if that). Seriously. Try it out to someone sometime and chances are, they’ll say the wrong answer that’s in this topic twice (so far). However I’ve had this topic on a board before and even then people get it wrong here and there in the replies. ---
### Author: ![kenner116](https://avatars.discourse-cdn.com/v4/letter/k/ecb155/32.png) [@kenner116](https://boards.straightdope.com/u/kenner116) #### Post date: [October 28, 2008, 2:23pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/12 "2008-10-28T14:23:44Z")
4100 ---
### Author: ![Inner\_Stickler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inner_stickler/32/318_2.png) [@Inner\_Stickler](https://boards.straightdope.com/u/Inner_Stickler) #### Post date: [October 28, 2008, 2:24pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/13 "2008-10-28T14:24:09Z")
4100 ---
### Author: ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean) #### Post date: [October 28, 2008, 2:26pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/14 "2008-10-28T14:26:07Z")
Cabbage ---
### Author: ![brewha](https://avatars.discourse-cdn.com/v4/letter/b/91b2a8/32.png) [@brewha](https://boards.straightdope.com/u/brewha) #### Post date: [October 28, 2008, 2:41pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/15 "2008-10-28T14:41:10Z")
First thought? 5000 But, knowing that my first thought is likely wrong and there is some trickeration going on here, I re-read it. 4090+10 != 5000 4100 is my final answer. ---
### Author: ![VanillaGorilla](https://avatars.discourse-cdn.com/v4/letter/v/f9ae1b/32.png) [@VanillaGorilla](https://boards.straightdope.com/u/VanillaGorilla) #### Post date: [October 28, 2008, 2:42pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/16 "2008-10-28T14:42:00Z")
4100 ---
### Author: ![Ann\_Onimous](https://avatars.discourse-cdn.com/v4/letter/a/ea5d25/32.png) [@Ann\_Onimous](https://boards.straightdope.com/u/Ann_Onimous) #### Post date: [October 28, 2008, 2:47pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/17 "2008-10-28T14:47:40Z")
1. ---
### Author: ![Ann\_Onimous](https://avatars.discourse-cdn.com/v4/letter/a/ea5d25/32.png) [@Ann\_Onimous](https://boards.straightdope.com/u/Ann_Onimous) #### Post date: [October 28, 2008, 2:48pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/18 "2008-10-28T14:48:42Z")
> [@Idle\_Thoughts](#): > > Probably..but you’re not the only one. 🙂 > [@Juliana](#): > > 1. Nope. Not the only one. And I’m even caffeinated. :smack: ---
### Author: ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth) #### Post date: [October 28, 2008, 2:51pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/19 "2008-10-28T14:51:45Z")
5000? \*\* Now looks around sheepishly if he screwed that up \*\* Knew that must have been a mind trick, but too lazy to go back and re-check my work. Sigh. ---
### Author: ![Baldwin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/baldwin/32/7264_2.png) [@Baldwin](https://boards.straightdope.com/u/Baldwin) #### Post date: [October 28, 2008, 2:52pm UTC](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932/20 "2008-10-28T14:52:13Z")
1. Did anybody say 5000? Ah. I was always good at simple math. Big disappointment when I got stuck halfway through calculus and found I’d never be a mathematician. [Next page](https://boards.straightdope.com/t/do-this-math-problem-in-your-head/469932.md?page=2)