# Number and string operations¶

## Numbers¶

References: - https://docs.python.org/3/tutorial/introduction.html#numbers - https://docs.python.org/3/tutorial/introduction.html#using-python-as-a-calculator

### Arithmetic operations¶

#### Addition¶

```
>>> 2 + 12
14
```

#### Subtraction¶

```
>>> 2 - 12
-10
```

#### Multiplication¶

```
>>> 2 * 4
8
```

#### Division, with a float as the answer¶

The division operator of `/`

returns a float (decimal) number by default:

#### Whole number division¶

To divide 2 numbers and only get a whole number, use a double forward-slash: `//`

```
>>> 11 // 7
1
```

#### Get the remainder of a division operation¶

This is also known as the **modulo** operation, which uses the percent sign as its operator:

```
>>> 7 % 5
2
```

### Built-in functions for numbers¶

#### Round a fractional number to the nearest n decimal places¶

Use `round`

and pass in a number as second argument indicating the number of decimal places to round to.

```
>>> round(8.23593, 1)
8.2
```

### Convert an integer to a float¶

Use the `float()`

class method and pass in an integer as an argument. The returned value will an equivalent number, but with a data type of float:

```
>>> float(42)
42.0
>>> type(float(42))
float
```

### Convert a float to an int; or, truncate a float to a whole number¶

Use the `int()`

class function to *truncate* a float – note that the result will be an integer, but not what you would get if you used the `round`

function:

```
>>> int(4.999)
4
```