Order of Operation Nation
Topics: Middle School, Math
In middle school math, students are required to memorize many formulas and processes, and using acronyms can be very helpful with these tasks. One such acronym, PEMDAS, can be used to remember the steps for Order of Operations. PEMDAS stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction, which is the order students must follow when finding the value of expressions. Here's how to practice PEMDAS, and help your middle schooler complete her homework in half the time!
Materials:
- multi-colored markers
- paper/pencil
Steps:
- At the top of the paper, ask your child to write the acronym PEMDAS, using a different color marker for each letter. Next to the word, write the symbol for the operation.
Parentheses ( )
Exponents n²
Multiplication •
Division ÷
Addition +
Subtraction - - Write a simple expression:
20 - 2² + (4 • 2) - Help your child find the value of the expression one step at a time.
- Start with P.
- Say: “Are there parentheses?” (yes)
Solve what is in parentheses first, rewrite expression:
20 - 2² + 8 - Put a check next to P.
- Say: “Are there exponents?” (yes)
Compute the exponent, rewrite expression:
20 – 4 + 8 - Put a check next to E.
- Say: “Is there multiplication?” (no) Put a check next to M.
- Say: “Is there division?” (no) Put a check next to D.
- Say: “Is there addition?” (yes)
Solve and rewrite the expression:
20 + 4
Solve. Answer is 24.
- Continue writing simple expressions, encouraging your middle-schooler to use PEMDAS as a checklist.
Tips:
- Once your child has mastered simple expressions using PEMDAS, ask her to find the value one expression two different ways. Compare the answers and note how important it is to follow PEMDAS.
- Post PEMDAS on the fridge or bulletin board to be sure your middle-schooler doesn’t forget this very important acronym.
Brigid Del Carmen has a Master's Degree in Special Education with endorsements in Learning Disabilities and Behavior Disorders/Emotional Impairments. Over the past eight years, she has taught Language Arts, Reading and Math in her middle school special education classroom.
Comments from readers
If you solve it the way it is written, you would have 4+8 = 12 then rewrite:
20 - 12 = 8.
If some one does not read the comments they are going to be very confused!!
Also, I teach "Please Excuse My Dear Aunt Sally" and use the first letters from this sentence, which I think is easier for kids to remember than just the letters.
20 - 4 + 8
16 + 8
Subtraction is performed 1st because it came before addition in left to right order.
24 Then addition.
As a middle school teacher this is a sore spot for me. Every year I get students who have somehow learned that you MUST always add before you subtract and you MUST always Multiply before you divide. My own son came home with the idea that you always multiplied before you divided. He was following the acronym of "Please Excuse My Dear Aunt Sally." So please, please, please be careful of how you teach this. The reason that this is important is because subtraction and division are not commutative. That is another lesson.