惨不忍睹的简单计算器窗口

这是一个不完整的代码，但我实在是找不出问题在哪里了。
求正解，，，，，
using System.Windows.Forms;

namespace 计算器
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public static int Count = 0;
        public static int right = 0;
        private void button4_Click(object sender, EventArgs e)
        {
            label2.Text = "/";
            RandomNum();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            label2.Text = "+";
            RandomNum();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            label2.Text = "-";
            RandomNum();
        }
        private void button3_Click(object sender, EventArgs e)
        {
            label2.Text = "*";
            RandomNum();
        }
        private void button5_Click(object sender, EventArgs e)
        {
            RandomNum();
        }
        private void RandomNum()
        {
            Random ran = new Random();
            int n1, n2;
            n1 = ran.Next(1, 11);
            n2 = ran.Next(1, 11);
            textBox1.Text = n1.ToString();
            textBox2.Text = n2.ToString();
            textBox3.Text = "";
            Count++;
        }


        private void button6_Click(object sender, EventArgs e)
        {
            textBox3.Enabled = false;
            Form2 frm2 = new Form2();
            frm2.ShowDialog();
        }
        private void textBox3_KeyDown(object sender, KeyEventArgs e)
        {
            int m;
         
            {


               
                m = int.Parse(textBox1.Text) + int.Parse(textBox2.Text);
             
                m = int.Parse(textBox1.Text) - int.Parse(textBox2.Text);
              
                m = int.Parse(textBox1.Text) * int.Parse(textBox2.Text);
               
                m = int.Parse(textBox1.Text) / int.Parse(textBox2.Text);
              

                if (e.KeyCode == Keys.Enter)
                {

                    if (textBox3.Text == m.ToString())
                        right++;
                    RandomNum();

                }
            }



        }

    
    }
}