diff --git a/calc/Calc_Test b/calc/Calc_Test
new file mode 100644
index 0000000000000000000000000000000000000000..e9845a75b665406148393cd10cdfb29baa9cfee6
--- /dev/null
+++ b/calc/Calc_Test
@@ -0,0 +1,17 @@
+import unittest
+from Calculator import Calculator
+
+class TestCalculator(unittest.TestCase):
+    def setUp(self):
+        self.calc = Calculator()
+
+    def test_add(self):
+        self.assertEqual(self.calc.add(2, 3), 5)
+        self.assertEqual(self.calc.add(-1, 1), 0)
+    
+    def test_sub(self):
+        self.assertEqual(self.calc.sub(5, 3), 2)
+        self.assertEqual(self.calc.sub(10, 4), 6)
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/calc/Calculator b/calc/Calculator
new file mode 100644
index 0000000000000000000000000000000000000000..e2302285eae651f32b097b893796d9ac885ac922
--- /dev/null
+++ b/calc/Calculator
@@ -0,0 +1,17 @@
+from abc import ABC, abstractmethod
+
+class ICalculator(ABC):
+    @abstractmethod
+    def add(self, a, b):
+        pass
+
+    @abstractmethod
+    def sub(self, a, b):
+        pass
+
+class Calculator(ICalculator):
+    def add(self, a, b):
+        return a + b
+
+    def sub(self, a, b):
+        return a - b
\ No newline at end of file