Reduce Drawcals

I have a grid of cubes like setted up with this code each of the cubes have a wolrdspace canvas to display a sprite if they are not used tu display a digit

     void Start () {
         var row = new GameObject();
         for (int x = 0; x < size; x++)
         {
             row = new GameObject();
             row.transform.parent = transform;
             row.name = "Row" + x;
             if (x >= 0 && x <= 3 || x >= 36 && x <= 39)
                 row.isStatic = true;
 
             for (int y = 0; y < size; y++)
             {
 
                 Vector3 pos = transform.position;
                 pos.x = x;
                 pos.y = y;
                 pos.z = 0;
                 GameObject o = Instantiate(obj, pos, transform.rotation) as GameObject;
 
                 if (x >= 0 && x <= 3)
                     o.isStatic = true;
                 o.transform.parent = row.transform;
                 o.name = "Cube(" + x + "," + y + ")";
                 objs[x, y] = o;
             }
         }
 
         wheater.Add("sun", Resources.LoadAll<Sprite>("sun"));
         Debug.Log(wheater["sun"].Length);
        
         digits.Add('1', ONE);
         digits.Add('2', TWO);
         digits.Add('3', THREE);
         digits.Add('4', FOUR);
         digits.Add('5', FIVE);
         digits.Add('6', SIX);
         digits.Add('7', SEVEN);
         digits.Add('8', EIGHT);
         digits.Add('9', NINE);
         digits.Add('0', ZERO);
 
         //ApplyTexture("sun");
     }

when i set a digit the cubes at the matching position move forward /backward

how would i reduce the neded draw calls