In this lesson, we will learn the PEMDAS rule for the order of operations. PEMDAS is the acronym for Parenthesis, Exponents, Multiplication, Addition and Subtraction.

Related Topics: Worksheets to help you practice the PEMDAS rule.

PEMDAS Rule

If the expression consists of parenthesis, exponents, +, –, × and ÷, then the operations MUST be performed in the following order.

Always work on the calculations within parenthesis first if any.

Next, calculate the exponents.

Then, carry out multiplication or division, working from left to right.

Lastly, do addition or subtraction, working from left to right.

The order to perform combined operations is called the PEMDAS rule.

Note: A common mnemonic for PEMDAS is Please Excuse My Dear Aunt Sally.

Example:

Evaluate 10 ÷ 2 + 12 ÷ 2 × 3

Solution:

Using the PEMDAS rule, we need to evaluate the division and multiplication before subtraction and addition. It is recommended that you put in parenthesis to remind yourself the order of operation.

10 ÷ 2 + 12 ÷ 2 × 3

= ( 10 ÷ 2) + (12 ÷ 2 × 3)

= 5 + 18

= 23

Videos

The following videos show more examples of the application of PEMDAS:

A more complicated example for the order of operations.

Learn one of the most important rules of math: the order of operations, also known as the PEMDAS rule.

Order of Operations (PEMDAS)

PEMDAS Songs

PEMDAS Song (with lesson) order of operations

PEMDAS Song with examples

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