Edit in JSFiddle

CalcModule = (function(){
                     var pub = {};
                      
                    pub.add = function(a,b){
                                 console.log('in add()',a,b);
                                 return a+b;
                    };
                     
                    pub.sub = function(a,b){
                                 console.log('in sub()',a,b);
                                 return a-b;
                    };
                     
                    return pub;
})();

alert CalcModule.add(5,2): 
<button onclick="alert(CalcModule.add(5,2))">5 + 2</button>
<br>
alert CalcModule.sub(5,2): 
<button onclick="alert(CalcModule.sub(5,2))">5 - 2</button>