Добавьте файлы проекта.

Form1.cs

@@ -0,0 +1,133 @@
+using calculator.View;
+
+namespace calculator
+{
+    public partial class Form1 : Form, ICaculatorView
+    {
+        public Form1()
+        {
+            InitializeComponent();
+        }
+
+        public event Action<char>? OperandPressed;
+        public event Action<string>? OperatorPressed;
+        public event Action<string>? SingleOperatorPressed;
+        public event Action? ClearPressed;
+        public event Action? CalculatePressed;
+
+        public void UpdateView(string input)
+        {
+            textBox1.Text = input;
+        }
+
+        private void OnCEButtonClick(object sender, EventArgs e)
+        {
+            ClearPressed?.Invoke();
+        }
+
+        private void OnZeroButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('0');
+        }
+
+        private void OnOneButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('1');
+        }
+
+        private void OnTwoButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('2');
+        }
+
+        private void OnThreeButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('3');
+        }
+
+        private void OnFourButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('4');
+        }
+
+        private void OnFiveButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('5');
+        }
+
+        private void OnSixButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('6');
+        }
+
+        private void OnSevenButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('7');
+        }
+
+        private void OnEightButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('8');
+        }
+
+        private void OnNineButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('9');
+        }
+
+        private void OnDotButtonClick(object sender, EventArgs e)
+        {
+            OperandPressed?.Invoke('.');
+        }
+
+        private void OnNegativeButtonClick(object sender, EventArgs e)
+        {
+            SingleOperatorPressed?.Invoke("-1");
+        }
+
+        private void OnPlusButtonClick(object sender, EventArgs e)
+        {
+            OperatorPressed?.Invoke("+");
+        }
+
+        private void OnMinusButtonClick(object sender, EventArgs e)
+        {
+            OperatorPressed?.Invoke("-");
+        }
+
+        private void OnMultButtonClick(object sender, EventArgs e)
+        {
+            OperatorPressed?.Invoke("*");
+        }
+
+        private void OnDivideButtonClick(object sender, EventArgs e)
+        {
+            OperatorPressed?.Invoke("/");
+        }
+
+        private void OnSqrtButtonClick(object sender, EventArgs e)
+        {
+            SingleOperatorPressed?.Invoke("√");
+        }
+
+        private void OnPercentButtonClick(object sender, EventArgs e)
+        {
+            SingleOperatorPressed?.Invoke("%");
+        }
+
+        private void OnInverseButtonClick(object sender, EventArgs e)
+        {
+            SingleOperatorPressed?.Invoke("1/");
+        }
+
+        private void OnEqualButtonClick(object sender, EventArgs e)
+        {
+            CalculatePressed?.Invoke();
+        }
+
+        private void button39_Click(object sender, EventArgs e)
+        {
+            
+        }
+    }
+}