<p>According to the UM bookstore website I need to get single variable calculus by james stewart UM edition. Isn't calc III multivariable, though? I have single variable calculus by james stewart non UM edition that I used for 156. Can I use it again for 255? Or does the UM edition have multivariable stuff in it?</p>
<p>Stewart has two textbooks as part of a “Calculus” series. The first book is single variable, and the second book is multivariable. You have the first one, and need the second one for Math 255. AFAIK, there’s nothing special about it being the “UM edition”.</p>