# The mathematics of eating out. **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [June 11, 2003, 9:08pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203 "2003-06-11T21:08:00Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [June 12, 2003, 1:38pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/21 "2003-06-12T13:38:44Z")
A pretty trivial calculation. These math games are all that way. It probably took about two minutes of work to set up. This one doesn’t even try to disguise the operation; the better ones at least make an attempt. The only amazing thing is that people are impressed by something like this. Did _everyone_ sleep through math class? ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [June 12, 2003, 2:15pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/22 "2003-06-12T14:15:52Z")
> [@](#): > > \*Originally posted by Muldoon III \* > \*\*I got that in an email last year (2002) saying that was the only year it would work. Does the year even matter? \*\* Sure it does, because of that ungainly 1752/1753. Take a look at what’s happening: Take a number: x Multiply by 2: 2x Add 5 (why exactly is 5 “for Sunday”?): 2x + 5 Multiply by 50: 100x + 250 Add 1753: 100x + 2003 Note the “2003.” That’s – not coincidentally, of course – the current year. Subtract the year you were born: 100x - (2003 - y) Now you will always get your age when you subtract the year you were born from the current year (unless you haven’t had your birthday yet, which is why there are two numbers to subtract). And when you multiply a number by 100, it moves the digits two places to the left, so X will appear in the 100s place. This is all highly unimpressive. You could easily add, say, “8” for Sunday and readjust the 1753 to make the thing work just as well. ---
**Author:** ![Scylla](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Scylla](https://boards.straightdope.com/u/Scylla)\ **Post date:** [June 12, 2003, 2:36pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/23 "2003-06-12T14:36:20Z")
I got 16,116. ---
**Author:** ![Monstre](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@Monstre](https://boards.straightdope.com/u/Monstre)\ **Post date:** [June 12, 2003, 8:30pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/24 "2003-06-12T20:30:16Z")
Wait, let me fire up the Bistromathic drive and check the results… ---
**Author:** ![John\_Carter\_of\_Mars](https://avatars.discourse-cdn.com/v4/letter/j/2bfe46/32.png) [@John\_Carter\_of\_Mars](https://boards.straightdope.com/u/John_Carter_of_Mars)\ **Post date:** [June 12, 2003, 11:26pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/25 "2003-06-12T23:26:16Z")
**Reality Chuck** : D’oh. And thanks. \*The sum total of all I retained from at least five different college math courses is that you can lay out a rectangular building foundation by using a 3,4,5 triangle. All else was lost forever as soon as my grade of “C” was posted…😛 ---
**Author:** ![Mama\_Tiger](https://avatars.discourse-cdn.com/v4/letter/m/6de8d8/32.png) [@Mama\_Tiger](https://boards.straightdope.com/u/Mama_Tiger)\ **Post date:** [June 12, 2003, 11:51pm UTC](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203/26 "2003-06-12T23:51:01Z")
> [@](#): > > \*Originally posted by RealityChuck \* > \*\*The only amazing thing is that people are impressed by something like this. Did _everyone_ sleep through math class? \*\* I didn’t sleep through it, but does sitting there watching the band practice their marching outside the window on the football field every day during math class count? [Previous page](https://boards.straightdope.com/t/the-mathematics-of-eating-out/181203.md?page=1)