Wrong result of JavaScript function (math operations)

Question

Can someone please breakdown this script for me and tell me how the outcome is 30105? Thanks alot guys

function one(numOneIn) {

two(numOneIn * 3); //1x3

document.write (numOneIn); //3

}

function two(aNumberIn) { 

document.write (aNumberIn); //1

}

function three(numIn) {

one(numIn * 2); 

document.write (numIn);

}

three(5);

Answer 1

three(5)

calls three, passing the number 5, then:

one(numIn * 2);

calls one, passing 5 x 2 => 10, then:

two(numOneIn * 3)

calls two, passing 10 x 3 => 30, then

two writes "30" as a string to the document.

Control returns to one, which writes the value passed to it (10) as a string.

Control returns to three, which writes the value passed to it (5) as a string.

So the final string is "30105".