# An interesting and obvious little maths ditty ... **URL:** \ **Category:** Cafe Society\ **Created:** [April 24, 2008, 3:37pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693 "2008-04-24T15:37:10Z")\ **Posts on this page:** 16\ **Page:** 1
**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:** [April 24, 2008, 3:37pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/1 "2008-04-24T15:37:10Z")
This actually happened to me, in real life, today. Boss gives you a long list of figures in a spreadsheet and asks you to total them - he still hasn’t found the auto sum button So you sum them and send it back - the bottom of the sheet looks a bit like this (note this is just the bottom end shown here - the total includes a longer list of items): ```auto ... sandwiches 120 beer 1020 hotels 13390 clothing 2300 fuel 5600 travel 200 ====== 53600 ``` You sum the column as shown and send the totalled sheet back to the boss, but he replies saying “wait - that last item - ‘travel’ is a reimbursement - it needs to be subtracted instead”. What’s the new total? ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [April 24, 2008, 3:39pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/2 "2008-04-24T15:39:53Z")
53,200? I don’t get it. ☹ ---
**Author:** ![Flander](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Flander](https://boards.straightdope.com/u/Flander)\ **Post date:** [April 24, 2008, 3:50pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/3 "2008-04-24T15:50:08Z")
53,200 if he’s paying it out or 53,400 if it’s simply being omitted. I think he’s pointing out the fact that he could have done that in his head in like 2 seconds instead of sending it back. ---
**Author:** ![Bosstone](https://avatars.discourse-cdn.com/v4/letter/b/22d042/32.png) [@Bosstone](https://boards.straightdope.com/u/Bosstone)\ **Post date:** [April 24, 2008, 4:06pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/4 "2008-04-24T16:06:56Z")
Aren’t all of those items reimbursements? It looks like an expense account tally. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [April 24, 2008, 4:07pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/5 "2008-04-24T16:07:25Z")
Oh. Got it. His boss must have a pointy head. 😃 ---
**Author:** ![sandra\_nz](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@sandra\_nz](https://boards.straightdope.com/u/sandra_nz)\ **Post date:** [April 24, 2008, 4:14pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/6 "2008-04-24T16:14:19Z")
53,200 woosh? ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [April 24, 2008, 4:20pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/7 "2008-04-24T16:20:20Z")
I don’t get it either. What’s the ditty? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 24, 2008, 4:44pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/8 "2008-04-24T16:44:46Z")
I don’t know what ditty he’s talking about, but I thought his point was that a chopped off top of a 2 looks exactly like the chopped off top of a 3 in that font. That would make the subtraction ambiguous if he didn’t have the rest of the numbers in front of him. But he does. Yep. I don’t get get it. ---
**Author:** ![RancidYakButterTeaParty](https://avatars.discourse-cdn.com/v4/letter/r/53a042/32.png) [@RancidYakButterTeaParty](https://boards.straightdope.com/u/RancidYakButterTeaParty)\ **Post date:** [April 24, 2008, 4:50pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/9 "2008-04-24T16:50:47Z")
I believe he is trying to point out that “most” people will give the answer $53,400, because they will simply subtract the 200 from the current total. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [April 24, 2008, 4:53pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/10 "2008-04-24T16:53:19Z")
Yeah, but a ditty is a poem or song, isn’t it? ---
**Author:** ![Flander](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Flander](https://boards.straightdope.com/u/Flander)\ **Post date:** [April 24, 2008, 5:14pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/11 "2008-04-24T17:14:12Z")
[QUOTE=RancidYakButterTeaParty] I believe he is trying to point out that “most” people will give the answer $53,400, because they will simply subtract the 200 from the current total. [/QUOTE] Kinda like I did before my brain caught me? 🙂 ---
**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:** [April 24, 2008, 8:03pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/12 "2008-04-24T20:03:23Z")
[QUOTE=Liberal] Yeah, but a ditty is a poem or song, isn’t it? [/QUOTE] Perhaps I meant something else. Dalliance, diversion or something. Anyway, what happened is this (this is all real, only the figures have been changed to the simplified versions above): Boss gives PA a spreadsheet of values to total (because he doesn’t know how PA doesn’t know either, so passes to employee X X totals and passes back up the chain Boss says “wait - that 200 is a credit - it needs to be subtracted instead” - passes spreadheet back to X (via PA) for correction. X prefixes the number with a minus sign - the total recalculates itself, X passes it back up the chain. Boss looks at total and notices it has gone down by 400 (not 200), declares “something is wrong with this”, and passes it to PA PA examines it and declares “Yes, something is wrong - you were only meant to subtract 200, but the total has gone down 400 from 53600 to 53200” X scratches head, receives splinters, calls IT support (me) and says “Excel isn’t totalling properly” I Examine spreadsheet, cannot find anything amiss, demonstrate that inserting the minus sign does indeed result in the 200 being subtracted instead of added, cannot discern the problem. X tries to explain - that’s when I realise what they’re all doing. I explain that 2+2+2=6, whereas 2+2-2=2 (not 4). Disbelief, realisation, embarrassment. X passes spreadsheet back to PA, explaining: 2+2+2=6, whereas 2+2-2=2 (not 4). Disbelief, realisation, embarrassment… Unfortunately, I didn’t get to witness the last part of the story, where it went back to the boss, but I think we can all probably imagine it. These people run the company I work for. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [April 24, 2008, 8:18pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/13 "2008-04-24T20:18:38Z")
Okay. Cool. But you did know this is CS, right? 🙂 ---
**Author:** ![Flander](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Flander](https://boards.straightdope.com/u/Flander)\ **Post date:** [April 24, 2008, 9:05pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/14 "2008-04-24T21:05:11Z")
[QUOTE=Liberal] Okay. Cool. But you did know this is CS, right? 🙂 [/QUOTE] The link to my bunny keeps it safe. 😉 ---
**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:** [April 24, 2008, 9:40pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/15 "2008-04-24T21:40:20Z")
[QUOTE=Liberal] Okay. Cool. But you did know this is CS, right? 🙂 [/QUOTE] Yeah, I meant to put it in MPSIMS, dunno what happened there. ---
**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:** [April 24, 2008, 10:33pm UTC](https://boards.straightdope.com/t/an-interesting-and-obvious-little-maths-ditty/446693/16 "2008-04-24T22:33:17Z")
No! Wait! It’s free verse! Yeah, that’s what it is.