A

**simple formula**is a mathematical expression with one operator, such as**7+9**. A**complex formula**has more than one mathematical operator, such as**5+2*8.**When there is more than one operation in a formula, the order of operations tells Excel which operation to calculate first. In order to use Excel to calculate complex formulas, you will need to understand the order of operations.**The order of operations**

Excel calculates formulas based on the following

**order of operations**:
Operations enclosed in

**parentheses****Exponential**calculations (3^2, for example)

**Multiplication**and division, whichever comes first

**Addition**and

**subtraction**, whichever comes first

A mnemonic that can help you remember the order is

**PEMDAS**, or**P**lease**E**xcuse**M**y**D**ear**A**unt**S**ally.
*NOTE: with Multiplication and Division, whichever operation comes first must be executed, also with Addition and Subtraction.

**Creating complex formulas**

In the example below, we will demonstrate how Excel solves a complex formula using the order of operations. Here, we want to calculate the cost of sales tax for a catering invoice. To do this, we'll write our formula as

**=(D2+D3)*0.075**in cell D4. This formula will add the prices of our items together and then multiply that value by the**7.5%**tax rate (which is written as**0.075**) to calculate the cost of sales tax.
Excel follows the order of operations and first adds the values inside the parentheses: (44.85+39.90) = $84.75. It then multiplies that value by the tax rate: $84.75*0.075. The result will show that the sales tax is $6.36.

Credits: Excel 2013