Ruby calls decimal numbers `Float`

s. To create a `Float`

rather than an `Integer`

, just make sure to include a decimal point:

```
5.class # => Integer
5.0.class # => Float
```

The math methods work mostly like you’d expect, and similarly to the ones for integers.

The main difference to keep in mind is with `/`

. Division with floats works the way that we’re used to — it returns fractional results, as a `Float`

:

```
12.0 / 5.0 # => 2.4
```

Try the following and see what you get:

```
12 / 5
12.0 / 5
12 / 5.0
```

What did you discover? If *either* side is a float, float division will be performed.

This is why `Integer`

’s `.to_f`

method can come in handy while doing math; at some point if you need to do division and need a fractional answer, then convert it to a `Float`

first.

One other thing to keep in mind: you can use `**`

in conjunction with fractions to calculate roots, since 9^{1/2} is the same as the square root of 9, 8^{1/3} is the same as the cube root of 8, etc.

```
9 ** 0.5 # => 3.0
8 ** (1/3.0) # => 2.0
```

`Float`

s can round themselves. Play around with the `.round`

method:

The `rand`

method that we met earlier can also be called with no arguments, in which case it returns a `Float`

between 0 and 1. This is very handy for e.g. probabilities. Give it a try: