Addition and Multiplication are said to be commutative, that is, changing the ORDER of the operations will not change the result obtained Example: + = + = × = × = However Subtraction and Division are NOT commutative Thus if we change the order of operations, the result will change Example: ? ? ? ÷ ? ÷
Define for students the right order of operations- PEMDAS- parentheses, exponents, multiplication or division as they occur from left to right, and then addition or subtraction as they occur from left to right There are few ways to memorize this rule: 1) Please Excuse My Dear Aunt Sally or 2) Purple Elephants May Destroy A School
In this lesson, we will learn the order of operations – Parentheses, Exponent, Multiplica-tion, Division, Addition, Subtraction 1 8 1 MD and AS Most likely, you remember from middle school the acronym PEMDAS (Please Excuse My Dear Aunt Sally) In order of operations, we should follow the order Parentheses, Expo-nent, Multiplication, Division
because multiplication is applied before addition, multiplication has a higher rank than addition Similarly, the exponent has a “higher rank” than multiplication Let’s practice using the order of operations with a few exercises Example 1: Evaluate each expression according to the Order of Operations
subtraction, multiplication, division, and exponents), there is an order that determines Before you get to the operations themselves, make sure that all the
4 addition and subtraction Operations that are equally important must be performed in order of occurrence (that is, from left to right) For example, if division comes before multiplication, division has to be done first Try these 1 22 + 2 82 −