As Seen by TV

I learned this a couple weeks ago, and I must admit that if you are planning a trip to China (and thinking about buying stuff), this comes in quite handy (!!!).
Numbers 0-5 are standard internationally, but 6-10 is where it can get tricky:

Although one should always learn to speak/understand the numbers.  Mandarin uses a simple formula, in that you only need to learn 11 seperate words to build and count numbers 0 to 99 (English/French/Spanish requires 28).  For example eight (8) is pronounced “ba”, while ten (10) is “shir”, so eighty (80) is “ba shir”, and eigthy-eight (88) is “ba shir ba”.  Of course keeping in mind that every “word” in Mandarin has 4+ tones, so pronouncing it correctly is another story, learn more precisely here.

DianHua is a great iPhone application for learning the numbers as well as general translations, get it free here.