**How do you use Excel to perform basic calculations?** Writting a formula in Excel is very simple but you must respect some rules to avoid mistakes

**Start your formula with the = symbol**In Excel, any formula or basic calculation starts with the = sign

**Respect the order of operations**Each mathematical operator doesn't have the same weight in an operation. In Excel, as in other programs, this order of operations must be respected

**Use the cell references**To simplify the writting of your formulas, you can select a cell to use its content.

## The = sign

In Excel, all the calculations or formulas start with the = sign. **It's COMPULSORY !!!**

## Add values

To add values in Excel, you just have to write an operation like this one in any cell.

=10+5

In the cell, you see the result and in the formula bar. Take care when you delete the contents of a cell; **you could delete a formula and not a value**.

## Subtract values

In the same way, to subtract values, you write a formula like this

=25-20

=20-25

## Multiplication and division

Here again, to make a multiplication or division, you have to write the operation in a cell, and you start with **the sign =**

=2*12 =>24

=50/10 =>5

## Order of operations

In mathematics, all the operators don't have the same "power". That's what is called the order of operations. Multiplication and division **have a stronger rank** than addition and subtraction.

The order of operations is

- The parenthesis
- Multiplication and division
- Addition and subtraction

### Explanation of a calculation with add and multiplication

What is the result of this calculation **2+3*4**? **20 is wrong!**

In fact, the multiplication is evaluated in Excel (and all the software) **before the add**.

- So first it's
**3*4=12** - And then,
**2+12=14**

And this is the result returns in the cell 😃

### Use parenthesis

If you want to **calculate the addition before the multiplication,** it's possible. For that, you must write the addition inside the parentheses

=(2+3)*4

This point is very important to calculate VAT for instance.

## Use reference in your formula

As you can see, in the previous example, we have used the reference of the cells to write our formula. These are the steps you must follow.

- Start with the
**=**symbol - Select the cell
**B4**with your**mouse** - Write the symbols
**/(1+** - Select the cell
**C1** - Press
**F4**to add the dollars. - Finish by closing the parenthesis

## Training online

- Training Guide: The Dollar Sign in Excel
- How to create a formula in Excel
- Excel Training – Create an Invoice
- Training with SUM, MIN, MAX and AVERAGE functions

## Facebook game

I'm sure you have seen this game in your Facebook timeline. But when you look at the answers in the comments, ... so many people don't respect the order of operations.

The solution is the following

- Row 1: 3 bottles of beer = 30.
- A bottle of beer it's 10 =30/3 (ok for every one? 😉)

- Row 2: 1 beer bottle + 2 hamburgers = 20
- We know that a beer bottle = 10
- So 2 hamburgers = 10 (20-10)
- 1 hamburger it's 5 =10/2

- Row 3: (here is the trick) 1 hamburger + 4 pints = 13
- 1 hamburger = 5
- Here we have 2 groups of 2 pints. So there is 4 pints
- So, 13-5 (the hamburger) = 8. And 8/4=2.
- The pint = 2

- Row 4: 1 hamburger + 1 pint * 1 beer bottle = ?
- So,
**you must respect the prior of the mathematical symbols** - 1 pint * 1 beer bottle => 2*10 = 20
- 20 + 1 hamburger => 20+5 = 25 😉

- So,