# Number and string operations¶

## Numbers¶

### Arithmetic operations¶

```>>> 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 nearest integer¶

Use `round`

```>>> round(9.99)
10
```

#### 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
```

## Strings¶

### Concatenate 2 strings together¶

Also known as “combine 2 strings”. The plus sign can be used for concatenation: