I would like to improve this sum using the `reduce` method, but I saw that works well for summing but also I have to do a subtract:

```
final = 0
@status.each do |data|
  final = final + data['pending_increase'] - data['pending_decrease']
end

```

The method I want to use is [`Enumerable#reduce`](http://ruby-doc.org/core-1.9.3/Enumerable.html#method-i-reduce)