numbers.js

function round(num, decimalplaces){
    return Number(num.toFixed(decimalplaces));
}

function randomInt(length){
    return Math.ceil((length || 2) * Math.random()) - 1;
}

function randomRange(min, max){
    return Math.random() * (max - min) + min;
}

function randomIntRange(min, max){
    return randomInt(max + 1 - min) + min;
}

function now(){
    return (new Date().getTime());
}