ELI5: Explain Like I'm 5

Gray's conjecture

Hey there kiddo! Have you ever heard of Gray's conjecture? It's a really interesting math problem that adults like to talk about.

So imagine you have a big number line with lots of little numbers on it. Gray's conjecture is all about looking at those numbers and figuring out which ones you can make by adding two perfect squares together.

Now you might be asking, "what's a perfect square?" Well, it's a number that you get when you multiply a whole number by itself. Like if you multiply 3 by 3, you get 9 - which is a perfect square!

So Gray's conjecture says that every number bigger than 33 is actually the sum of two perfect squares. That means you can add two numbers that are perfect squares together to get any big number you want!

But here's the tricky part - even though lots of smart grown-ups have tried to prove this conjecture, nobody has been able to do it yet. That's why it's still called a conjecture instead of a theorem. But maybe someday someone will be able to figure it out!

So that's Gray's conjecture in a nutshell - it's all about adding perfect squares together to make big numbers, and trying to figure out if every big number can be made that way. Cool stuff, huh?