test.html

<!doctype html>
<html ng-app>
  <head>
    <link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.0.2/css/bootstrap.min.css">
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.2/angular.min.js"></script>
    <script src="http://underscorejs.org/underscore-min.js"></script>
    <script>
function CnvCtrl($scope, $sce) {
  document.getElementById('allInput').focus();
  $scope.results = [];
  $scope.allInput = '';

  var dummy = {value:undefined, show:false};
  var convertors = [toCelcius, minPerMilesToKmph, elapsedSong, milesPerDay];

  $scope.$watch('allInput', function() {
    $scope.results = _.map(convertors, function(f) {
       var r = f($scope.allInput);
       r.unit = $sce.trustAsHtml(r.unit);
       r.show = r.show || !isNaN(r.value);
       return r;
    });
  });

  return;

  function round(x, n) {
    var precision = n || 2;
    return Math.round(x * Math.pow(10, precision)) / Math.pow(10, precision);
  }

  function toCelcius(arg) {
    if (arg === undefined || arg === '') {
      return dummy;
    }
    // (Â°F  -  32)  x  5/9 = Â°C
    return {value: round((arg - 32) * 5 / 9.0), unit:'&deg;C'};
  }

  function minPerMilesToKmph(arg) {
    if (arg === undefined || arg === '') {
      return dummy;
    }

    var argv = _.map(arg.split(':'), function(x) {
      if (x === '') return 0;
      return parseInt(x);
    });

    if (argv.length > 2) {
      return dummy;
    }

    if (argv.length === 1) {
      argv[1] = 0;
    }

    if (_.some(_.map(argv, function(x) { return typeof n !== 'number' || x < 0 || x >= 60; })))
      return dummy;

    // x mpm => 60*1.60934/x kmph
    return {value: round(60 * 1.60934 / (argv[0] + argv[1]/60.0)), unit:'km/h'};
  }

  function elapsedSong(arg) {
    var data = ['4:06',  '8:42',  '13:20', '19:46', '24:58', '29:41', '34:28',
                '39:21', '44:22', '50:36', '55:32', '59:40', '65:09', '70:18'];
    var argv = arg.split('+');
    var song_idx = argv[0];
    var r = data[parseInt(song_idx)];
    return {value: r, unit:'', show: r !== undefined};
  }

  function milesPerDay(achievedMiles) {
    var remainingMiles     = 100 - parseFloat(achievedMiles);
    var currentDate        = new Date();
    var dayOfMonth         = new Date().getUTCDate();
    var daysInCurrentMonth = new Date(currentDate.getUTCFullYear(), currentDate.getUTCMonth(), 0).getDate();
    var remainingDays      = daysInCurrentMonth - dayOfMonth;
    var r                  = round(remainingMiles / remainingDays, 2);
    return {value: r, unit:' miles/day', show: r !== undefined && !isNaN(r)};
  }
}
</script>
</head>
<body>
  <div ng-controller="CnvCtrl">
  <div class="container"><div class="row"><div class="col-xs-12">
      <input type="text" id="allInput" ng-model="allInput" placeholder="Enter something here" class="form-control">
       </div></div></div>
      <div class="list-group">
        <a href="#" class="list-group-item" ng-repeat="result in results track by $index"
          ng-show="result.show">{{result.value}}<span ng-bind-html="result.unit"></span></a>
      </div>

    </div>
  </body>
</html>