Wolfram Problem Generator is the latest tool from the computational search engine (Wolfram Alpha), that I just found out about from the great blog, Educational Technology Guy. This is a wonderful site for Math teachers/students that are looking to solve problems in a wide range of areas (i.e., order of operations, division, calculus, etc.). Also, WPG allows users to create printable worksheets as well as set the difficult of their problems to beginner, advanced, or intermediate.
I highly recommend checking out Wolfram Problem Generator by clicking here!!!