Adding and subtracting all the arguments in a function

addsub.js

function sum(){
    var result = 0,
        i = 0,
        len = arguments.length;
    
    while (i < len){
        result += arguments[i];
        i++;
    }
    return result;
}
function takeaway(){
    var result = arguments[0],
        i = 1,
        len = arguments.length;
    
    while (i < len){
        result -= arguments[i];
        i++;
    }
    return result;
}
console.log(takeaway(1,3,2,2,4,1));