Please forgive my title, I really don't know how to phrase it better.

This isn't a school assignment or anything, but I realize it's a mostly academic question. But, what I've been struggling to do is parse 'math' text and come up with an answer.

For Example - I can figure out how to parse '5 + 5' or '3 * 5' - but I fail when I try to correctly chain operations together.

(5 + 5) * 3

It's mostly just bugging me that I can't figure it out. If anyone can point me in a direction, I'd really appreciate it.

EDIT Thanks for all of the quick responses. I'm sorry I didn't do a better job of explaining.

First - I'm not using regular expressions. I also know there are already libraries available that will take, as a string, a mathematical expression and return the correct value. So, I'm mostly looking at this because, sadly, I don't "get it".

Second - What I've tried doing (is probably misguided) but I was counting '(' and ')' and evaluating the deepest items first. In simple examples, this worked; but my code is not pretty and more complicated stuff crashes. When I 'calculated' the lowest level, I was modifying the string.

So... (5 + 5) * 3

Would turn into 10 * 3

Which would then evaluate to 30

But it just felt 'wrong'.

I hope that helps clarify things. I'll certainly check out the links provided.