Lambda the Ultimate

Hi, was wondering if someone could explain more in detail about "combinatory logic" in a simplistic way. I am not a programmer, I do 3-D animation and I fell into Lambda Calculi while reading I believe an article about a video games that mentioned something about functional progaming. Anyway I started getting an interested in Lambda Calculi and I found a lot of articles about it online. It took me a while to understand it but when I did, the concept around it seemed rather easy. Now I'm trying to learn how combinatory logic works, but there isn't as much material on it as there is with Lambda Calculi. Usually it is lumped into a Lambda Calculi article without much dedication to it. Or I find it talked about in a programing languages such as "unlambda" but as I am not a programming, so I get confused. I started to "get" Lambda Calculi, when I started learning how Church numbers work, and saw examples of how to do simple arthritic like adding and multiplying. So far I can't find anything like this with combinatory logic, can someone show examples of how to make numbers with combinatory logic and to do something like add or multiply with it? This would be a great help.