Math (Order of Operations) or PEMDAS Step by Step is an interactive app the teaches the order of operations in a math expression. PEMDAS stands for Parentheses, Exponents, Multiplication/Division, Addition/Subtraction. Other variations for PEMDAS are: BEDMAS, BODMAS, and BIDMAS. - This app will show you how to evaluate a math expression in the right order. - You can type your own expressions or let the app generate ones for you - Two modes of interaction 1) Multiple choice option where you have to pick the right answer for the step 2) You can go to next, back, first or last step - You can turn on or off sounds.