Overview
On this page, we investigate the correct order of arithmetic operations, using the memory aid “PEMDAS” (which some like to remember as “Please Excuse My Dear Aunt Sally”).
Basic Learning Objectives
These are the tasks you should be able to perform with reasonable fluency when you arrive at your next class meeting. Important new vocabulary words are indicated in italics.
 Recall the order of operations convention used to evaluate numerical expressions, often abbreviated as PEMDAS (“Please Excuse My Dear Aunt Sally”).
Advanced Learning Objectives
In addition to mastering the basic objectives, here are the tasks you should be able to perform after class, with practice:
 Apply the correct order of operations to completely evaluate a complex numerical expression.
To prepare for class

Watch the following video (by Tyler Wallace) which introduces the order of operations PEMDAS:

Watch the following videos (by Tyler Wallace) which explain in more details how to apply PEMDAS with (nested) parentheses and absolute values:
After class

Watch the following video (by Tyler Wallace) which shows some more complicated examples, including one with a fraction: