Math.PI;
    Math.round(num);        ----> returns closest integer
    Math.pow(a,b);          ----> Returns a^b
    Math.sqrt(num);         ----> Returns Square Root 
    Math.abs(num);          ----> Returns the absolute value
    Math.ceil(num);         ----> Returns the high next integer
    Math.floor(num);        ----> Returns the low next integer
    Math.max(a, b, c, d);   ----> Returns the highest value
    Math.min(a, b, c, d);   ----> Returns the lowest value
    Math.random();          ----> Returns a value between 0 and 1

function randBetween(min,max){
    max = Math.ceil(max);
    min = Math.floor(min);
    return Math.floor(Math.random() * (max-min)) + min;
}
var a = 6;
var b = 200;

console.log(randBetween(a,b));