[Old Pedant]

Do you *MEAN* turn off? In that case, instead of just changing the 0 to "" wouldn't you want to change the div's style to "display: none;"??

BUt anyway:

var divs = document.getElementsByTagname("div");
for ( var d = 0; d < divs.length; ++d )
{
    var div = divs[d];
    if ( div.innerHTML == "0" ) 
    {
        div.innerHTML = "";
        // or 
        div.style.display = "none";
    }
}

Note that this will process *ALL* the <div>s on your page.

If possible try to somehow "contain" them.

Example:

<div id="onlyLookHere">
    <div>8</div>
    <div>5</div>
    <div>0</div>
    <div>6</div>
    <div>0</div>
    <div>0</div>
    <div>1</div>
</div>

and then do:

var divs = document.getElementById("onlyLookHere").getElementsByTagname("div");
for ( var d = 0; d < divs.length; ++d )
{
    var div = divs[d];
    if ( div.innerHTML == "0" ) 
    {
        div.innerHTML = "";
        // or 
        div.style.display = "none";
    }
}