1.2 Learn Basic Properties and Operations
This lesson will help you learn the basic properties and rules that govern math problemsolving.
Order of Operations
When an expression has more than one operation, the order that you perform the operations could affect the answer.
Consider this expression:  $$8 + 4 \times 5$$ 
If you add first, the answer is 60.  
If you multiply first, the answer is 28. 
Mathematicians have agreed upon a set of rules for solving problems with more than one operation. The rules are called the order of operations.

To remember these steps, many people memorize this acronym, or memory trick: Please Excuse My Dear Aunt Sally (PEMDAS). The letters stand for parentheses, exponents, multiplication, division, addition, and subtraction.