right-bind.js

var partialRight = function(fn){
  var args = [].slice.call(arguments);
  var partiallyFilledArguments = args.length > 1 ? args.slice(1, args.length) : [];

  return function(){
    var remainingArgs = [].slice.call(arguments);
    return fn.apply(null, remainingArgs.concat(partiallyFilledArguments));
  }
}

function add(){
  var vals = [].slice.call(arguments);
  return vals.reduce(function(curr, val){
    return curr+val;
  },0);
  
}

var add2 = partialRight(add, 1,2,3);
var add3 = partialRight(add2, 4,5,6)

console.log(add3(7)); // 28