Test

HTML

<div ng-controller="MyCont" ng-app>
    <input type="number" min="0" max="50" value="{{value}}" ng-model="value" />
    <input type="range" min="0" max="50" value="{{value}}" ng-model="value" />
    <input type="text" value="{{value}}" ng-model="value" />
    {{value}}
</div>

JavaScript

function MyCont($scope) {
    $scope.value = 0;
    
    $scope.$watch('value',function(val,old){
       $scope.value = parseInt(val); 
    });
};