**Excel is a very easy-to-use tool that lets you quickly enter information into cells.**

**But it's just as easy to make formulas, as we'll see in this article.**

## Start your formula with the = sign

The = sign is THE WAY to explain to Excel that you will perform a calculation. No matter whether you're performing a simple operation or calling up an Excel function, it will always start with an equal sign.

You can use the following sign for your basic calculation

- + for addition
- - for subtraction
- * for multiplication
- / for division

Example of basic calculations in Excel

The last example is very interesting because here, we can see that Excel respect the order of operations.

- The multiplication 20*2 is calculated first
- Then, the addition 100+40 (the result of the multiplication)

And of course, you can change the order of operations with parentheses. Parenthetic subexpressions are evaluated first. You have here 2 times the same calculation but with, or without the parentheses, the result is different

## Use reference instead of value

But of course, if your workbook stores values in cells, it's much better to reused them into your calculation. In the following example, to calculate the result of the first quarter, we can write the following formula

=B2+B3+B4

The technique to write the previous formula is very simple

- Write the = sign
- Go to the cell B2 (or click on B2 with the mouse)
- Press the + sign
- Go to the cell B3
- Press the + sign
- Go to the cell B4
- Press the Enter key to validate your formula

And you can use any cell of your workbook, from any worksheet. For example, you can write your formula in one sheet with the data in another worksheet. Here, in the cell B1 of the Sheet4, we build our formula with the data of the Sheet3.

=Sheet3!B2+Sheet3!B3+Sheet3!B4

Again, you don't need to write the write manually the reference of the cells. You can take your mouse and select the cell in the other worksheet, Excel will write the reference automatically in the formula bar.

## Use the Excel function

There is more than 500 functions in Excel and it's impossible to know all of them 😉 To use them

- Start with the = sign
- Write the name of the function, like SUM
- Open a parenthesis.

Or

- Start with the = sign
- Write the name of the function, like SUM
- Select the name of the function you want to use
- Autocomplete the name with the Tab Key. Not only you complete the name of the function but also, you open the parenthesis