sumscomponent

components.my-sums.js

import Ember from 'ember';

export default Ember.Component.extend({
  sums: Ember.computed('x', 'y', function() {
  	return {xy: this.get('x') + this.get('y')};
  })
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{#my-sums x=5 y=6 as |s|}}
  <h2>X + Y = {{s.xy}}</h2>
{{/my-sums}}
<br>
<br>

templates.components.my-sums.hbs

{{yield sums}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}