How to pass argument from Flame.js widget to ember function

I am learning ember.js and flame.js for the first time, and am having trouble understanding some of the documentation. I have a flame widget (a button) which when clicked, should send a argument (the number 1) to the function specified in action. The flame code is given below:

           numButtonView: Flame.ButtonView.extend({
                layout: { left: 150, width: 20 },
                title: '4',
                targetBinding: '^controller',
                action: 'numDisplay'
            })

and the ember function right now looks like this:

numDisplay: function(num){
     ......
},

How do I pass the 'argument' from the widget to the function? I would be glad for any help,..thanks in advance!