# Lösung: Eigenclass einer Klasse


```ruby
class Numeric
  class << self
    def to_binary(n)
      n.to_s(2)
    end
  end
end

puts Numeric::to_binary(47)
```

Alternative Lösung:

```ruby
class << Numeric
  def to_binary(n)
    n.to_s(2)
  end
end

puts Numeric::to_binary(47)
```