Learning CoffeeScript

Supposedly I want to declare a closure nested method in JavaScript like this:

###Sample1
//declaration
 function addInternal(x)
 { 
    //return anonymous nested function
     return function(y) { console.log(x+y);};
 }

//use
var addByTen  = addInternal(10);
addByTen(15);

.

or wrap it up as a variable

###Sample2, assign the parameter to outer function addInternal in declaration
var addByTen  = (function addInternal(x)
{
    //return anonymous nested function
    return function(y){console.log(x+y);};
})(10);

//use
addByTen(15);


The corresponding CoffeeScript version is very tight:

###sample1
addInternal = (x) ->
 (y) -> console.log x+y

addByTen = addInternal 10
addByTen 15

###sample2
addByTen = ((x) ->
 (y) -> console.log x+y ) (10)

addByTen 15