So the objective is to make some buttons the size of 20% of the width & height of the screen. In regular Famo.us, this works:

```
var ww = window.innerWidth * .2;
var hh = window.innerHeight * .2;

// later in the code

for(var i = 0; i < 2; i++) {
 surfaces.push(new Surface({
    content: "button",
    size: [ww, hh]
}));

```

However, in Angular when I use fa-size in the HTML, it's not calculating my objects:

```
<fa-modifier ng-repeat="item in list"
   fa-size="[ww, hh]"
   fa-origin="[0.5, 0.5]"
   fa-align="[0.5, 0.5]">
   <fa-surface fa-background-color="item.bgColor">
     {{item.content}}
   </fa-surface>
</fa-modifier>

```

In the Angular Controller I have:

```
angular.module('famousAngularStarter')
  .controller('MainCtrl', function ($scope, $famous) {

    var Transitionable = $famous['famous/transitions/Transitionable'];
    var Easing = $famous['famous/transitions/Easing'];
    var ww = window.innerWidth;
    var hh = window.innerHeight;

    $scope.myGridLayoutOptions = {
       dimensions: [2, 3]
    };
});

```
['https://Stackoverflow.com/questions/25805883', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/4033895/']
`CMD + N -> iOs -> Cocoa Touch -> Objective-C Class`
To create a Objective-C class, you have to select **"Cocoa class"**. This will create an .h and .m file for you. Alternatively you can manually add a "Header file" with the same name, but thats just more work for the same thing.