My lesson from last Friday discussed the order of operations (often called PEMDAS), but without any exponents. Today I'll give examples with exponents included. Out of 15 middle school tests this year, this concept appeared 16 times--usually as question # 8.
Number Dojo Level: 106
When solving a mathematical expression, there are certain rules that dictate how we move through the process. The purpose of these rules is to ensure that everyone who evaluates the same expression comes up with the same answer. Otherwise, math would be subjective instead of objective. And for people like me, that would be a big problem--I want to know when I'm right! (Except now that I've been married 20 years as of tomorrow, I've learned that in terms of marital conflict, even when I'm right, I'm wrong!) :)
This year on high school tests, problems involving basic order of operations (not including special variations--like estimates or fractions in disguise) showed up 13 times, usually around question # 8. For some reason, these questions rarely involved exponents this year, so I've decided to leave those out for this lesson and cover them next for middle school.
The Order of PEMDAS
- Multiplication & Division
- Addition & Subtraction
How to use PEMDAS
- First, look for any parentheses and solve the expression inside first.
- Second, handle any exponents (and roots).
- Third, solve any multiplication and division operations, going left to right.
- Finally, solve the addition and subtraction parts, going left to right.