I’ll start off by saying I’m new to Ember so if this is supported in another way then I welcome clarification.

I ran into a use case where I needed the total of values from related ED models. However, I discovered that I basically needed to loop through each relation to add its value to the total, using reduce:

```
totalNumber: function(){
return this.get('relatedModels').reduce(function(total, relation){
return total + relation.get('numberValue');
}, 0);
}.property('relatedModels.@each.numberValue')
```

But wouldn’t it be great if we could reduce that to just one line using the Ember.computed.sum helper?

```
totalNumber: Ember.computed.sum('relatedModels.@each.numberValue')
```

Doesn’t seem to work for me, but again maybe I’m just doing it wrong. I would imagine other computed helpers would benefit from this functionality as well.