I'm doing some research for an algorithm, and I have a lot of curiosity, too. I'd like to learn how limits are calculated by mathematicians and mathematical software. I understand calculus somewhat, but I'm a litty rusty on it and I sometimes get perplexed by calculations involving limits. What's my best bet for learning about how limits are calculated? Should I review my calculus, or is there more science to limits (like numerical methods?!?)?