Mathematically correct way to cut cake

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  • Опубликовано: 7 авг 2023
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Комментарии • 876

  • @markusr3259
    @markusr3259 10 месяцев назад +5251

    A mathematicians birthday party must be a very complicated affair.

    • @robinbrowne5419
      @robinbrowne5419 10 месяцев назад +10

      Ha ha. Yes indeed :-)

    • @limitingchaos
      @limitingchaos 10 месяцев назад +111

      That's why mathematicians should have at least 56 friends, so the probability of at least two people sharing the birthday is nearly 1.

    • @happmacdonald
      @happmacdonald 10 месяцев назад +35

      Depends on the mathemetician. The most elegant solution in this circumstance is just have nearly no friends. xD

    • @Packerfan130
      @Packerfan130 10 месяцев назад

      cuz 50% of the time, theyre sharing the bday with 100 other people :P

    • @JujuLand0
      @JujuLand0 10 месяцев назад +7

      @@limitingchaosand then we can add the extra complexity of multiple cakes, with potential for flavor preference too

  • @Jona69
    @Jona69 10 месяцев назад +4609

    Just put the cake in a blender and give everyone an equally full glass of cake.

    • @kurtangeloballarta5866
      @kurtangeloballarta5866 10 месяцев назад +111

      tf

    • @WyzrdCat
      @WyzrdCat 10 месяцев назад +649

      No fair, mine was half empty but hers was half full

    • @tabainsiddiquee7611
      @tabainsiddiquee7611 10 месяцев назад +591

      @@WyzrdCat You got the wrong address, the Philosophers' birthday party is next door

    • @qwertyTRiG
      @qwertyTRiG 10 месяцев назад +25

      Drinkable cake (for consumption at the pink lake, with Sam Denby).

    • @iamdigory
      @iamdigory 10 месяцев назад +40

      The cake's real mother will not agree to that

  • @wncjan
    @wncjan 10 месяцев назад +1473

    There is no fair way to divide a cake as no matter how it's divided, I want everything

    • @neezduts69420
      @neezduts69420 10 месяцев назад +60

      *soviet anthem plays*

    • @Lattamonsteri
      @Lattamonsteri 10 месяцев назад +13

      I guess fairness has different meanings for different people :D

    • @wncjan
      @wncjan 10 месяцев назад +20

      @@Lattamonsteri There is no sich thing as fairness when it comes to sharing cake - or bacon

    • @sagestrings869
      @sagestrings869 10 месяцев назад +3

      i guess we just need to buy the bakery instead

    • @sanketjadhav3.14
      @sanketjadhav3.14 9 месяцев назад +2

      As above comment said , put it in a mixer/grinder
      Give everyone glass of cake😂

  • @jackhandma1011
    @jackhandma1011 10 месяцев назад +942

    Oppenheimer tried to cut the cake down to the atomic level back in the 1940's. He realized it isn't a good idea.

    • @BoredInNW6
      @BoredInNW6 10 месяцев назад +71

      "I am become death, destroyer of cake"

    • @georgewang2947
      @georgewang2947 9 месяцев назад +10

      It was yellowcake

    • @ehssandariani8041
      @ehssandariani8041 9 месяцев назад +4

      @@georgewang2947that is an Iranian specialty 😂

    • @anonymouscode1635
      @anonymouscode1635 7 месяцев назад +1

      I thought Japanese loved it

    • @pryme0
      @pryme0 7 месяцев назад +3

      ​@@anonymouscode1635the cake division ceremony was held there but they were not informed. I assume they don't like it

  • @shatterthemirror8563
    @shatterthemirror8563 10 месяцев назад +1175

    Queen "Let them eat cake"
    Masses: Well that's just not gonna cut it"

    • @tyapca7
      @tyapca7 10 месяцев назад +18

      Queen: "They don't have bread? Why don't they eat cakes?" Attributed to Marie Antoinette, but, traced back to Rousseau. Well, I'm not a historician. And as always, thanks for the video. P.

    • @irfaanfarhat
      @irfaanfarhat 10 месяцев назад +6

      Sounds like an Adrian Bliss Skit lmao

    • @WokerThanThou
      @WokerThanThou 10 месяцев назад +18

      ... that's just not going to cut it. However, we found something that will. It's called a guillotine.

    • @PlasticSinks
      @PlasticSinks 10 месяцев назад

      ​@@irfaanfarhat100% immediately imagined him saying it

    • @user-pr6ed3ri2k
      @user-pr6ed3ri2k 10 месяцев назад

      Cut

  • @DanielRossellSolanes
    @DanielRossellSolanes 10 месяцев назад +102

    best way?
    ask my mother to make the cuts.
    I still wonder how she manages to make them so perfect. as far as I know, never has anybody complained about it.

    • @fahrenheit2101
      @fahrenheit2101 9 месяцев назад +12

      Well, what if nobody's complained and lived to tell the tale...

  • @SteveJubs
    @SteveJubs 10 месяцев назад +236

    I have absolutely been the one to cut the cake and then still envy the piece the other person chose lol

    • @trucid2
      @trucid2 10 месяцев назад +16

      Skill issues.

    • @SteveJubs
      @SteveJubs 10 месяцев назад +7

      @@trucid2 human error, 100%

    • @J-sv9dp
      @J-sv9dp 10 месяцев назад +7

      @@SteveJubsGrass is always greener… even when perfectly cut 🙃

    • @SteveJubs
      @SteveJubs 10 месяцев назад +2

      @@J-sv9dp best reply

    • @princesslucillaa
      @princesslucillaa 7 месяцев назад

      me every time coz i hope they don’t notice ones slightly bigger

  • @debtanaysarkar9744
    @debtanaysarkar9744 10 месяцев назад +192

    Now, that's a "sweet" math problem, LoL 😂😂😂😂

  • @akshatrawat8461
    @akshatrawat8461 10 месяцев назад +73

    you had my attention at "imagine you have a cake"

    • @rubiks6
      @rubiks6 7 месяцев назад +1

      Jade should have hearted this one, too.

  • @WaluigiisthekingASmith
    @WaluigiisthekingASmith 10 месяцев назад +124

    The best part is while the upper bound in n^n^n^n^n^n while the lower bound is just n^2

    • @cubing7276
      @cubing7276 10 месяцев назад +5

      when mathematicians have skill issue

    • @McFrax
      @McFrax 10 месяцев назад +2

      Frankly, n^2 is still a lot.

    • @meisterschiumpf9759
      @meisterschiumpf9759 10 месяцев назад +14

      @@McFrax we're talking about very small numbers here. For n=2 already, lower bound is 4 but 2^2^2^2^2 already is a number with 19729 digits. I think you can see, that upper bound=2^(number with 19729 digits) is gonna be very large compared to 4. Also, upper bound grows much much faster...
      btw, the number of atoms in the known Universe has about 80 digits.

    • @Krranski
      @Krranski 10 месяцев назад

      "skill issue", he says! @@cubing7276

    • @juanhaver6584
      @juanhaver6584 8 месяцев назад +2

      Wait didn't 3 people do if in 5 cuts or less than n^2 (9)

  • @nandodando9695
    @nandodando9695 10 месяцев назад +65

    If you are at a mathematical festival, always choose the first toilet. No-one else will.

    • @darbyl3872
      @darbyl3872 10 месяцев назад +5

      Ye Olde' Secretary Outhouse Problem

    • @jacobc9221
      @jacobc9221 7 месяцев назад +4

      "Mathematician festival" makes them sound like they have an entire culture lol

  • @OngoGablogian185
    @OngoGablogian185 10 месяцев назад +64

    I'm going to need to buy quite a few cakes to really get to the bottom of this.

  • @GarryBurgess
    @GarryBurgess 10 месяцев назад +10

    I'm impressed that mathematicians have abstracted that problem in the first place, let alone solved it.

  • @johnbonnett5746
    @johnbonnett5746 10 месяцев назад +26

    When I was studying Mathematics at Adelaide in the 1960s, this problem was posed in a paper for our Measure Theory course. After all, this problem is about the gastronomic value measure each of the eaters apply to different parts of the cake. A cutter, who may be one of the eaters, makes a radial cut in the cake and poises the knife over slowly rotating it, keeping the point in the centre, so sweeping out a sector of cake. The scrupulously honest eaters continuously integrate their measure of the value of the sector and call out when it reaches their fair share, i.e., 1/nth of the cake. The first to call out obviously values the piece more than the others, so there should be enough for the others to get at least their fair share. The cut is made, and the piece handed over, and the process is repeated to satisfy the desires of the remaining eaters.

    • @larrykuenning5754
      @larrykuenning5754 10 месяцев назад +3

      This is logically equivalent to (and physically less messy than) the solution in my comment, which I also remember from the 1960s (no later than 1966). Jade, your history does not go back far enough!

    • @johnbonnett5746
      @johnbonnett5746 10 месяцев назад +1

      @@larrykuenning5754 That sounds right to me. The last year of my formal mathematics was 1967. I'm sorry I did not notice your reply before.

    • @larrykuenning5754
      @larrykuenning5754 10 месяцев назад +1

      @@johnbonnett5746: My reply was later than your comment by about a day; it looks like you noticed it as soon as was reasonable and there's nothing to be sorry about. I'm glad our memories line up on the general nature of the proof and the approximate time period. If only we could find some actual documentation to cite from that period -- but probably neither of us had any reason to preserve bibliographical notes on the subject.

    • @christopherwellman2364
      @christopherwellman2364 7 месяцев назад

      now, apply that to warfare responsibilities amongst the U.N.

    • @rfvtgbzhn
      @rfvtgbzhn 7 месяцев назад

      So it only works if people are honest. So maybe at a birthday party where all people are friends, but definitely not when dividing resources as claimed in the video.

  • @ignorasmus
    @ignorasmus 10 месяцев назад +21

    I am glad you mentioned about the metaphor thing.
    In one of the previous videos about a goat grazing half of the field, I made a joke about the engineer's approach and thousands of people seem to have taken it seriously and called mathematicians stupid 🤦‍♂️
    Dear Mathematicians (And other scientists in general), as an engineer, I can not be more grateful for the foundation that you that you lay for us to build upon!

  • @hassaanbukhari517
    @hassaanbukhari517 10 месяцев назад +18

    I tried this with my wife and she ate up the whole cake. Thank you Jane!

  • @Anuchan
    @Anuchan 10 месяцев назад +35

    A cake is a metaphor for all the resources my mother has given me. And when she isn't looking, I take an extra slice, symbolizing my dissatisfaction with being fair.

  • @jessicaheger1880
    @jessicaheger1880 8 месяцев назад +6

    This is why cupcakes are awesome. Everyone just picks one and the leftovers go home with the birthday child.

  • @electric_chris
    @electric_chris 7 месяцев назад +2

    It doesn't matter how accurately or fairly you cut the cake; someone will always complain

  • @philochristos
    @philochristos 10 месяцев назад +12

    Maybe instead of cutting the cake, we should cut one of the people. That reduces the number of people you need to cut cake for, therefore simplifying the problem.

    • @leandrog2785
      @leandrog2785 7 месяцев назад

      But then you have the problem of dividing the person among the others.

    • @TraderMatt89
      @TraderMatt89 6 месяцев назад

      That escalated quickly

  • @dibenp
    @dibenp 10 месяцев назад +7

    Step 1: assume the cake is a sphere. 😂

    • @vishnuchandrabose9875
      @vishnuchandrabose9875 День назад

      Step 2 : And let the volume of of cake is infinite, problem solved

  • @donnieji4825
    @donnieji4825 8 месяцев назад +1

    My goodness... to be able to listen to you while eating your cake sounds like a dream 😜

  • @sanjay.d3496
    @sanjay.d3496 10 месяцев назад +14

    That way I eat whole cake 😂

  • @bramverhees755
    @bramverhees755 10 месяцев назад +20

    Now I want cake :(

    • @romilgoel4191
      @romilgoel4191 9 месяцев назад +2

      The cake is a lie.

    • @KS-xx5xq
      @KS-xx5xq 8 месяцев назад +2

      And there is no spoon.

  • @G_Mustafa
    @G_Mustafa 10 месяцев назад +7

    Cutting it in atoms and divide it 😅

  • @Piper_____
    @Piper_____ 8 месяцев назад

    I love the simplicity of “one person cuts, the other chooses.” Immediate incentive for the cutter to make the cut as fair as possible.

  • @BradTheThird
    @BradTheThird 10 месяцев назад +10

    This sounds like less of a maths problem and more like humans being difficult.

    • @renato360a
      @renato360a 10 месяцев назад +4

      you can remove the human factor. For example, you want to draw a blueprint for a new bedroom with bathroom and balcony in your house, but you have to decide three shapes to "cut" the floor on the second story, to strike a balance between the three areas. No ones being difficult there, and you want to make the best use of your hard earned money.

  • @handsfree1000
    @handsfree1000 10 месяцев назад +1

    The accountants are getting their slice first and leaving us with the crumbs

  • @albirtarsha5370
    @albirtarsha5370 9 месяцев назад +1

    Parent: Here's your cake. If you don't want it, I will eat it for you.

  • @oscarbizard2411
    @oscarbizard2411 10 месяцев назад +3

    The team of researchers still wasn't able to enjoy a meal together.

  • @daniellevy2272
    @daniellevy2272 9 месяцев назад +1

    Ah yes, math and its importance displayed in full power

  • @penewoldahh
    @penewoldahh 9 месяцев назад +1

    Siblings will cut the cake in an infinite number of pieces to make it fair

  • @john_hunter_
    @john_hunter_ 10 месяцев назад +5

    I think you need to make a full length video about this. What are the limitations for the scenario? Does everyone value a different aspect of the cake or can they all value the same thing?

    • @deeprecce9852
      @deeprecce9852 10 месяцев назад +1

      There is a good video from RUclips channel Numberphile titled " Equally sharing a cake between 3 people'

  • @gabedarrett1301
    @gabedarrett1301 10 месяцев назад +5

    I kinda want to know how to cut the cake when there are 3 people

    • @danielyuan9862
      @danielyuan9862 8 месяцев назад +1

      I recall a numberphile video on exactly that. I forget what it's called, but I'm sure you can find it!

  • @colinjava8447
    @colinjava8447 10 месяцев назад +1

    Let's hope Graham's number of people don't want to share a big cake equally then.

  • @trigonzobob
    @trigonzobob 10 месяцев назад +1

    Mathematically correct. Technically the best kind of correct.

  • @benjamingoldstein1111
    @benjamingoldstein1111 10 месяцев назад +2

    That was much clearer than the first short on the envy-free-cake-cutting. Great job!

  • @meatlemonade3338
    @meatlemonade3338 7 месяцев назад

    one of my favorite things about mathematicians is how they will come up with the most unhinged way to cut something and it's always so much fun

  • @MattFromHawaii
    @MattFromHawaii 7 месяцев назад +1

    This is so interesting and humorous for me, because I recently saw this diagram about how to cut cake in an equal way so that the cake (from a circle) equally can be distributed to how ever many people there are lol actually was really interesting imo.
    Basically it showed the cake being cut by circles, from the inside to out or whichever, then having those rows be individually cut to a specific size

  • @jigglypuff_foryoutube1700
    @jigglypuff_foryoutube1700 8 месяцев назад +1

    When I was a kid, my parents always made sure that kids got the pieces they wanted. For example, we had a rectangular sheet cake and a kid at my birthday party wanted this very specific piece right in the middle. So, my mom cut the piece right out from the center. She always said “What’s more important: a neatly cut cake or a happy kid?”

  • @well...5943
    @well...5943 3 месяца назад

    I love this channel bc you tell us problems that have been solved but nothing about the solution, not even the equation

  • @calbarog
    @calbarog 8 месяцев назад

    I have pondered this problem for many years. Thank you for talking about it!

  • @LaClimSx
    @LaClimSx 8 месяцев назад

    I never realized cake cutting was a metaphor, I’ve always thought mathematicians were just interested in ways to cut cake

  • @perpetualengine
    @perpetualengine 10 месяцев назад +1

    Ah yes, the cake smoothie. Perfectly devided and distributed.

  • @LesHaskell
    @LesHaskell 10 месяцев назад +1

    Always have an engineer cut the cake. They know how to round up and down.

  • @Idkmwahaha
    @Idkmwahaha 8 месяцев назад +1

    The only thing about the two person cutting of the cake is that the two people tend to argue on who will cut and who will choose

  • @nerdest
    @nerdest 7 месяцев назад +1

    when people are jobless enough to write such complex pieces of code

  • @Flyhigh099
    @Flyhigh099 10 месяцев назад +1

    Hey I think this re-upload is much clearer in explaining the concept.. Thank you for introducing a new concept for me...👌

  • @fredhubbard7210
    @fredhubbard7210 9 месяцев назад +1

    Thanks for this... This question has haunted me since I was a young boy, so always refused to let anyone bake me a cake for my birthday. Finally, I can get my own birthday cake.

  • @swordsbyasa-punk
    @swordsbyasa-punk 10 месяцев назад +8

    I too, as a philosopher, take the problem seriously. I recommend the "Quit whining & enjoy what you get" philosophy & applying it to all cake people! 😂

  • @SurprisinglyDeep
    @SurprisinglyDeep 7 месяцев назад

    One moral of the lesson: Just bring plain cakes with no decorations on it to a gathering of mathematicians.

  • @2122345able
    @2122345able 8 месяцев назад +1

    Forget the cake , I just fell in love with her

  • @lycaptain
    @lycaptain 3 месяца назад

    three mathematicians are having a party and a fourth walks in…

  • @kepspark3362
    @kepspark3362 9 месяцев назад +1

    I eat entire cakes alone sometimes.😂

  • @Respectable_Username
    @Respectable_Username 8 месяцев назад

    Now I'm imagining the absolute scene when it's somebody's birthday in the maths department and one of the juniors/grad students naïvely brings in a cake to celebrate 😂

  • @Praharshkstudios
    @Praharshkstudios 9 месяцев назад +1

    Thing is, everyone will still be envious because everyone always want more cake.

  • @1203raj
    @1203raj 9 месяцев назад

    I am glad they solved it. Been sitting here with this cake for the past 40 years. I can finally move on to doing laundry.

  • @MisterJackTheAttack
    @MisterJackTheAttack Месяц назад

    My immediate question was "how many dimensions do we have to work with?"

  • @presidentskroob522
    @presidentskroob522 5 месяцев назад

    I love the little hair flick at the start of every video lol

  • @TheRealMirCat
    @TheRealMirCat 10 месяцев назад +2

    More people need to watch Labyrinth. "Life isn't and will never be fair."

  • @iloveplasticbottles
    @iloveplasticbottles 7 месяцев назад

    "for two people, it's a cakewalk"
    😂

  • @moajjem04
    @moajjem04 7 месяцев назад

    so that's why mathematicians have only three people in birthday parties.

  • @Legendarybruh
    @Legendarybruh 7 месяцев назад

    It's always the computer scientists.

  • @lupita3689
    @lupita3689 7 месяцев назад +1

    That’s why the best outcome is achieved by mutual compromise.

  • @abhranilroy9180
    @abhranilroy9180 10 месяцев назад

    Ah so this is how old Marie Antoinette trolled the masses and lost her bonnet in the process

  • @avideosomeday3913
    @avideosomeday3913 9 месяцев назад

    "Why do u want her slice?? theyre all mathematically calculated and perfectly cut"
    "I want 2"

  • @SteveMarcus91
    @SteveMarcus91 8 месяцев назад

    I, for one, remember the Numberphile Cake Video Incident.

  • @sket179
    @sket179 9 месяцев назад +1

    A diplomat could have solved this problem in a heartbeat. Former German chancellor Ludwig Erhard is quoted by saying: "A compromise is the art of dividing the cake so that each person thinks they got the biggest part."
    I was tasked this as a kid regularly. I was given a bag of assorted candy, and I needed to divide it three ways between my dad, baby sister and I. Inknew what candies they liked, so I was usually left with the set I planned on having. Same with portioning ice cream into bowls. I think this made me who I am currently. Or messed me up, or both. 😂

  • @godsamongmen8003
    @godsamongmen8003 9 месяцев назад

    "Imagine you have a cake..."
    Hold that thought, I'm making a quick run to the bakery.

  • @aboxthatdrools
    @aboxthatdrools 5 месяцев назад +1

    You know, you could just... not share the cake. That's an option.

  • @WTH1812
    @WTH1812 10 месяцев назад

    "You'll get nothing and like it. Now who else wants to complain?" This solves the problem.

  • @Mr.Miloeditz99
    @Mr.Miloeditz99 7 месяцев назад +1

    Me buying a cake with just frosting 💀💀

  • @shridharangp4865
    @shridharangp4865 3 месяца назад

    Thanks for teaching us maths in an easy to understand way ❤❤

  • @user-mr2hq8gd8s
    @user-mr2hq8gd8s 10 месяцев назад +1

    Is this what computer scientist really does?

  • @Ebvardh
    @Ebvardh 8 месяцев назад

    Call me when mathematicians discover how to have your cake eat it too.

  • @cfmcguire
    @cfmcguire 9 месяцев назад

    I am standing there with a twelve-inch chef's knife, you aren't. You will take the slice I give you.

  • @cneer17
    @cneer17 7 месяцев назад

    Mathematicians will do anything but figure out how to communicate lol

  • @sirjohn6299
    @sirjohn6299 7 месяцев назад +1

    I know how to solve this problem. Invite a bunch of Mathematicians to a party and get a really nice cake. Ask the smartest Mathematician to cut the cake perfectly, watch them all argue, then steal the cake and leave.

  • @oversatisfied_aether
    @oversatisfied_aether 6 месяцев назад +1

    The best way is to give everyone a full cake

  • @ribesjordi
    @ribesjordi 4 месяца назад

    You explain things beautifully! It must be hard to explain this problem and find ways to summarize the assumptions (if the weight on the cake is continuous or not, if it depends on the participant, if cuts are restricted somehow, in which order participants cut and choose, if they can skip choosing, blah blah...) and not bore your audience. I would like to have the skill to do that graphically and just saying the bare minimum, as you do.
    A follow up on that "it's more complicated but it can be done in 5 cuts" would be nice.

  • @edwardpaddock2528
    @edwardpaddock2528 10 месяцев назад

    RNG fixes everything.

  • @domanicjordan
    @domanicjordan 8 месяцев назад

    Instructions unclear. Now I have a smoothie

  • @voidanims
    @voidanims 9 месяцев назад

    Sometimes i think mathematicians are insane, just cut the cake

  • @presidiun
    @presidiun 7 месяцев назад

    Love your videos. Momentarily I am back at university. Thank you.

  • @merkazoidduff7651
    @merkazoidduff7651 7 месяцев назад

    Solved by the axiom ‘you get what you get and you don’t throw a fit’.

  • @HsinTsungChu
    @HsinTsungChu 10 месяцев назад

    Sounds so interesting! Would definitely love to see a full video on this :)

  • @c.jishnu378
    @c.jishnu378 7 месяцев назад

    It's weird to imagine that working on the collatz conjecture is thought to be more silly than this.

  • @ablanccanvas
    @ablanccanvas 8 месяцев назад

    Brilliant discussion! 👍🏽♥️

  • @acarrascoy
    @acarrascoy 7 месяцев назад

    One of the nicest math books I've ever read was called precisely that "How to cut a cake (and other mathematical conundrums)" 😄

  • @miracle9726
    @miracle9726 7 месяцев назад

    Mathematicians must have run out of problems to solve

  • @raezor82
    @raezor82 10 месяцев назад

    When I see someone cut a round cake not towards the center I almost have an aneurysm.

  • @christopherwellman2364
    @christopherwellman2364 7 месяцев назад

    I always wondered how to fairly divide which countries' military duties in war.

  • @Safa.is.in.her.bubble
    @Safa.is.in.her.bubble 6 месяцев назад

    She got me in the beginning 😂

  • @FishKungfu
    @FishKungfu 3 месяца назад

    "I was told there would be cake." ~Milton

  • @PixelTrainer.
    @PixelTrainer. 9 месяцев назад

    "Hey, no fair! I wanted that atom of the cake!"

  • @ADEpoch
    @ADEpoch 10 месяцев назад

    I quote from the TV show Numb3rs, "What's wrong with you mathematicians? Cake is never a problem."

  • @samchristianlazarra
    @samchristianlazarra 3 месяца назад

    *Casually Divides up chores to the billionth power* 💀

  • @ajreukgjdi94
    @ajreukgjdi94 10 месяцев назад

    The ham sandwich theorem sounds like a better solution to this. Just add more cuts (and more spatial dimensions) for each person

  • @KaustavMajumder
    @KaustavMajumder 9 месяцев назад

    I was happily studying Gaussian Kernel distribution, and here we are. Right then, back to studying.

  • @ii795
    @ii795 10 месяцев назад

    Wow, what a simple recepe for 2-person case. Never occured to me before. I will suggest this now to my children next time they need to share something (fortunately, I only have two!)