encoding decoding cells into a single number inside fixed dimension discrete rectangular grid

var dx = 10;
var dy = 10;
var dz = 3;

var decode = function(v)
{
   var z = v % dz;
   var xy = (v - z) / dz;
   var y = xy % dy;
   var x = (xy - y) / dy;
   console.log('out', x, y, z);
}

var encode = function(x, y, z)
{
   console.log('in', x, y, z);
   return (x * dy + y) * dz + z;
}

for (var x = 0; x < dx; x++)
{
   for (var y = 0; y < dy; y++)
   {
      for (var z = 0; z < dz; z++)
      {
         decode(encode(x, y, z));
      }
   }
}