- Parentheses
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Order
This mnemonic helps us remember which order to complete mathematical operations. The order in which a problem is solved is crucial. Without having a set order, we would arrive at different results."No!" you say. Well, look at the following problem.
2 + 3 x 6
Is the answer 30? 2 + 3 = 5. 5 x 6 = 30.
This is why we need to learn the mnemonic Please Excuse My Dear Aunt Sally. If not, we would not know the correct answer to the above is 20!
Yes, the answer is 20. Our mnemonic tells us which order to solve the problem. We do not just read right to left as if it were an English sentence. Multiplication comes before addition in the mnemonic (My comes before Aunt), therefore, we must multiply before we add.
If we do that, then our answer is 20! 3 x 6 = 18. 18 + 2 = 20.
