protected void FormulaController_onSelectCell()
 {
     try
     {
         currentValue.text = "=" + StaticMethods.NumberFormat(formulaController.ExpressionExecuted);
         currentNodes.Clear();
         currentNodes.AddRange(formulaController.Serialize());
         currentButton.image.sprite = Sprites[2];
     }
     catch
     {
         currentButton.image.sprite = Sprites[1];
     }
 }