private void BttnResta_Click(object sender, EventArgs e)
{
operador = "-";
first = double.Parse(TxtPantalla.Text);
TxtPantalla.Clear();
}
private void BttnMultiplicacion_Click(object sender, EventArgs e)
{
operador = "*";
first = double.Parse(TxtPantalla.Text);
TxtPantalla.Clear();
}
private void BttnBorrarPantalla_Click(object sender, EventArgs e)
{
TxtPantalla.Clear();
}
