A number is a data type.

We want to say that `x`

is a number.
It can take a set of values (for example 1, 10, 42, -100, `y`

).

To write this in python:

```
x = 5
```

Now we can see the value of x by:

```
x
```

A practical example: we have 2 numbers, and we want to perform fast operations with them.

```
x = 2
y = 3
x + y # add
x * y # multiply
x ** y # x to the power of y
```

The results should be 5, 6 and 8.

The # is used to mark the rest of the text of that line as a comment.

As you can see, python instructions do not end with semicolumn (;) as in other languages, and the instructions are written on different lines.

`x`

and `y`

are called variables.

We can check the data type of a variable by using the `type`

keyword:

```
x = 2
x # the computer displays 2
type(x) # computer: <class 'int'>
```

`int`

is the truncated form of *integer* which is the set of integer numbers.
We can also use rational numbers:

```
almost_pi = 3.14
type(almost_pi) # computer answer: <class 'float'>
```