Presentation on theme: " Order of Operations Algebra Seminar 2012-2013. When do we use Order of Operations? If you’ve only got one or two operations in an equation, it’s pretty."— Presentation transcript:
When do we use Order of Operations? If you’ve only got one or two operations in an equation, it’s pretty simple to see what to do first, then second. Once you get into more complicated equations, however, you need the Order of Operations. To help remember the order, remember the following sentence: Please excuse my dear aunt sally.
Evaluate 7 + 4 3 Is your answer 33 or 19? You can get 2 different answers depending on which operation you did first. We want everyone to get the same answer so we must follow the order of operations.
Please Excuse My Dear Aunt Sally The first letter of each word reminds us of the order: Please – P stands for Parentheses (grouping symbols) Excuse – E stands for Exponents My – M stands for Multiplication Dear – D stands for Division Aunt – A stands for Addition Sally – S stands for Subtraction
PEMDAS Parentheses Exponents Multiplication, Division, Addition, and Subtraction are done from left to right.
Evaluate the expression when x=4. Start with the expression Substitute in 4 everywhere you see an x Use PEMDAS! Parentheses first Finish parentheses, next is exponents! Multiply next. Finish up!
Experiment Use the expressions Arrange grouping symbols (parentheses) to make this expression equal: 146 54 38 Don’t change the order of the values!
Example #1 Using the left – to – right rule: 24-8-6 Using the left – to – right rule: 30+5-2 Using the left – to – right rule: 18-20+3-2
Calculator Test Enter this into your calculator If you got 6.1 then your calculator automatically does the order of operations for you. If you got 0.6 then your calculator does not use order of operations and you’ll need to use the parentheses when you enter equations into your calculator.