private void Reciprocal_btn_Click(object sender, EventArgs e)
 {
     Op_lbl.Text  = Reciprocal_btn.Text;
     Lhs_lbl.Text = textBox1.Text;
     Tape_txtBox.AppendText(Lhs_lbl.Text + "\n");
     textBox1.Clear();
     calc.Reciprocal_entered();
     Ans_lbl.Text = calc.Equals().ToString();
 }
        private void reciprocal_Click(object sender, EventArgs e)
        {
            //calculator.Number_entered(Convert.ToDouble(display.Text));
            //display.Text = calculator.Reciprocal_entered();
            //isNewNumberEntered = true;
            //temp_History += display.Text;

            temp_History       = calculator.Number_entered(Convert.ToDouble(display.Text));
            display.Text       = calculator.Reciprocal_entered();
            isNewNumberEntered = true;
            history.Text      += "1/" + temp_History + "=" + display.Text + "\n";
            temp_History       = "";
        }