Lemma (mathematics)

Okay kiddo, imagine you have lots of building blocks of different shapes and sizes. Some are big and square, some are small and round, and some are in the middle.

Now, let's say you want to build a tower using these blocks, but you don't have enough of one kind of block to make the tower as tall as you want. What do you do? Well, you can use a smaller block as a building block to build the tower, but you need to figure out how many of these smaller blocks you need to use to be able to build the tower to the right height.

In math, we have a similar situation when we are trying to prove something. We have some big ideas that we need to prove, but we may not have enough information to do so directly. So we need to use smaller, simpler ideas to help us prove the bigger idea.

This is where a lemma comes in. A lemma is like a small building block, or a little puzzle piece, that we can use to help us build the bigger idea we are trying to prove. It's a small idea that we can prove easily, and then use that proof to help us prove the larger idea.

Think of it like building a tower with blocks - you start with the small blocks and use them to build up to the big idea you need. And just like with building blocks, you can use several different lemmas to help you build your proof, just like using different types of building blocks to create your tower.