整数的四则运算

namespace JiSuanQi
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public static int Count = 0;
        public static int Right = 0;
        private void RandomNum() 
        {
            Random rad = new Random();
            int m1,m2;
            m1 = rad.Next (1,101);
            m2 = rad.Next (1,101);
            textBox1 .Text = m1 .ToString ();
            textBox2 .Text = m2 .ToString ();
            textBox3 .Text = "";
            Count ++;
        }
        private void jisuan() 
        {
            Random js = new Random();
            int a, b;
                a = js.Next(11);
                b = js.Next(11);
                textBox1.Text = a.ToString();
                textBox2.Text = b.ToString();
                Count++;
        }
        private void textBox4_KeyDown(object sender, KeyEventArgs e) 
        {
            string fuhao;
            fuhao = textBox4.Text;
            if (fuhao == "+")
            {
                 lable1.Text = "+";

            }
               
            else if (fuhao == "-")
            {
                lable1.Text = "-";

            }
            else if (fuhao == "*")
            {
                 lable1.Text = "*";
            }
           else
           { 
                label0.Text = "/";
            }
        }
            private void button1_Click(object sender ,EventArgs e)
            {
                jisuan ();
            }
            private void textBox3_KeyDown(object sender,EventArgs e)
            {
                int txt3;
                if (textBox4.Text == "+")
                {
                    txt3 = int.Parse (textBox1.Text )+int.Parse (textBox2 .Text );

                }
                else if (textBox4.Text == "-")
                {
                    txt3 = int.Parse (textBox1.Text )-int.Parse (textBox2 .Text );
                }
                else if (textBox4.Text == "*")
                {
                    txt3 = int.Parse (textBox1.Text )*int.Parse (textBox2 .Text );
                }
                 else 
                {
                    txt3 = int.Parse (textBox1.Text )/int.Parse (textBox2 .Text );
                }
                if (e.KeyCode == Keys .Enter )
                {
                    if(textBox3 .Text ==txt3 .ToString ())
                    {
                         right++;
                         textBox3 .Text ="";
                         jisuan ();
                    }   
                }
            }
        }
    }
}
namespace JiSuanQi
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e) 
        {
            textBox3.Enabled = false;
            new Form2().ShowDialog();
        }

        public partial class Form2 : Form 
        {
            public Form2() 
            {
                InitializeComponent();
            }
            private void Form2_Load(object sender, EventArgs e) 
            {
                textBox1.Text = Form1.Count.ToString();
                textBox2.Text = (((Form1.right) / (double)(Form1.Count)) * 100).ToString() + "%";
            }
        }      
    }