Hierarchy (mathematics)

Okay kiddo, imagine you have a stack of blocks. The blocks at the bottom are big and heavy, and the blocks on top are smaller and lighter. You can stack the blocks in different ways, but there will always be a biggest block at the bottom and a smallest block at the top.

In math, we also have something called a hierarchy. Instead of blocks, we have numbers or things called sets. Some of these numbers or sets are bigger or more important than others. We can organize them in a hierarchy to help us understand which ones are more important.

For example, imagine we have the set of all animals in the world. At the very top of the hierarchy, we have a set called "vertebrates" which includes all animals with a backbone. Beneath that, we have "mammals" which are a type of vertebrate that give birth to live young and nurse them with milk. Beneath mammals, we have "primates" which are a type of mammal with opposable thumbs and a big brain. And finally, at the bottom of the hierarchy, we have "humans" which are a type of primate that can talk, use tools, and do all sorts of complicated things.

So just like how the blocks were stacked on top of each other, we can stack sets or numbers in a hierarchy to show which ones are more important or bigger than others.