Order of Operations

In math, we have to have a set way of solving problems, otherwise everyone could get different answers. “Order of Operations” is simply a list of steps to use when solving problems with multiple operations (operations are adding, subtracting, multiplying, dividing).

The easiest way to remember the order is to use this acronym:

  • Please
  • Excuse
  • My
  • Dear
  • Aunt
  • Sally

These letters stand for:

  • Parentheses
  • Exponents
  • Multiply
  • Divide
  • Add
  • Subtract

Multiplying and dividing go as a pair: if you have both of these operations, solve them from left to right. The same is true for adding and subtracting; if you have both, solve from left to right.

We will use the letters P, E, M, D, A, S as shorthand for the operations.

Example math problems related to order of operations:

  1. 5 + 7(4 – 2)
    • First, identify the operations: we have A, M, S, and P. According to the order of operations, we must first start with the parentheses, which is where the subtraction is:
    • 5 + 7(2)
    • Now we multiply:
    • 5 + 14
    • Finish up by adding:
    • 19
  2. 18 ÷ 3 + 5(7 – 4) x 2
    • Identify the operations: D, A, M, P, S, and M.
    • Start with the parentheses:
    • 18 ÷ 3 + 5(3) x 2
    • Now we see that we have D, A, M, and M.
    • Since we have both dividing and multiplying, we will do those from left to right:
    • 6 + 15 x 2
    • 6 + 30
    • Then add:
    • 36
    • To avoid confusion, first look for parentheses. Solve those parts, then look for exponents. After that, dividing and multiplying, and finally, adding and subtracting.
  3. 4 x 52 + 16 ÷ 2
    • This time we have exponents, so start with that:
    • 4 x 25 + 16 ÷ 2
    • Now we’ll do multiplying and dividing:
    • 100 + 8
    • Then add:
    • 108