ELI5: Explain Like I'm 5

Fair division among groups

Imagine you have a box of cookies and you want to share them with your friends. But you have to make sure everyone gets a fair share so no one feels left out or upset.

To make it fair, you can divide the cookies into equal groups. For example, if you have 10 cookies and 5 friends, you can divide the cookies into 5 equal groups of 2 cookies each.

But what if everyone likes different types of cookies? To make it fair, you can let each friend choose which type of cookie they want. This way, everyone gets a fair share of the type of cookie they like best.

Now, let's say you have more cookies than friends, and some cookies are more valuable than others. To make it fair, you can use a method called "fair division." This means that everyone gets an equal chance to choose the most valuable cookies.

One way to do this is called "divide and choose." You divide the cookies into equal groups, and one person gets to choose the first group. Then the next person chooses from the remaining groups, and so on, until everyone has chosen a group. This way, everyone has an equal chance to choose the most valuable group of cookies.

In summary, fair division means dividing things equally so everyone gets a fair share. You can make it even fairer by letting everyone choose what they want or by using a method like "divide and choose."