How to write numbers in words

I have trouble writing numbers out in words, for instance in writing a check.

I have found an iPhone app and a website to help me with this problem. You enter the number and it converts it into words for you.  

To go to the CheckMate app - here

To go to the Really Big Numbers website click here

Can you say really big numbers? math cats explore (1) Enter a big number. (It can even be bigger than this box!) (This number can be rounded to: ) (2) Say the number out loud. (3) See how to write it. (4) Read it out loud and check: did you say it correctly?? Attention please! The Math Cats name large numbers the American way. Many countries in Europe use another system. The MegaPenny Project shows you lots and lots of pennies, up to one quintillion! And there's a chart showing how to name numbers up to 1 followed by 120 zeros. (After your visit, close the MegaPenny Project window to return to Math Cats.) copyright 2003 - 2012 by Wendy Petti of Math Cats and Maurici Carbó Jordi of Nummolt. All Rights Reserved.