An expression is a command that returns a value. For example, if our command adds two numbers together then the valued returned is their sum.

In [1]:

```
2 + 2
```

Out[1]:

If the command is to get the absolute value of a number, it returns the absolute value.

In [2]:

```
abs(-2)
```

Out[2]:

The order of operations for mathmatical operations is the standard order.

In [3]:

```
3 + 5 * 2
```

Out[3]: