Simple formulas have one mathematical operation. Complex formulas involve more than one mathematical operation.
The order of mathematical operations is important. If you enter a formula that contains several operations—like adding, subtracting, and dividing—Excel knows to work those operations in a specific order. The order of operations is:
1. Operations enclosed in parentheses
2. Exponential calculations (to the power of)
3. Multiplication and division, whichever comes first
4. Addition and subtraction, whichever comes first
Relative to the order, you will also calculate from left to right. Let's look at an example: 2*(6-4) =?
Is the answer 8 or 4? If you calculated in the order in which the numbers appear, ignoring the parentheses, 2*6-4, you'd get the wrong answer, 8. You must follow the order of operations to get the correct answer.
To calculate the correct answer:
1. Calculate the operation in parentheses: 6-4=2.
2. Multiply 2*2=4.
3. The answer is 4.
When using formulas, the results change each time the numbers are edited.
In Excel, never do math in your head and type the answer in a cell where you would expect to have a formula calculate the answer.