how to position two divs above each over

Is there any way to start drawing divs from the same point? That means if I add new div and then I add another div, they will appear above each other. Because I want to move them all together depending on the same point.

CSS:

#num1,#num2{
    display : inline
    position:relative;
    left:50px;
}

HTML:

<div id='container'>
    <div id='num1'></div>
    <div id='num2'></div>
</div>

So what should I add to this code so when the browser render this code the 2 divs will be on the same place?