diff --git a/solutions/add_numbers.py b/solutions/add_numbers.py
new file mode 100644
index 000000000..d3deb8957
--- /dev/null
+++ b/solutions/add_numbers.py
@@ -0,0 +1,39 @@
+# add_numbers.py
+
+"""
+This module provides a function to add two numbers.
+
+Function:
+    - add_numbers: float: The sum of the two numbers.
+Created on: January 6, 2025
+@author: Melat Assefa
+"""
+
+
+def add_numbers(a: float, b: float) -> float:
+    """
+    Calculate the sum of two numbers.
+
+    Parameters:
+    a (float): The first number to add. It can be any real number.
+    b (float): The second number to add. It can be any real number.
+
+    Returns:
+    float: The sum of the two numbers.
+
+    Raises:
+    TypeError: If either of the arguments is not a number.
+
+    Examples:
+    >>> add_numbers(2, 3)
+    5
+    >>> add_numbers(-1, 1)
+    0
+    >>> add_numbers(0.5, 0.5)
+    1.0
+    """
+
+    if not isinstance(a, (int, float)) or not isinstance(b, (int, float)):
+        raise TypeError("Both arguments must be numbers.")
+
+    return a + b
diff --git a/solutions/tests/test_add_numbers.py b/solutions/tests/test_add_numbers.py
new file mode 100644
index 000000000..bf8a2928f
--- /dev/null
+++ b/solutions/tests/test_add_numbers.py
@@ -0,0 +1,64 @@
+# tests/test_add_two_numbers.py
+
+"""
+Unit tests for the add_two_numbers function.
+This test suite includes:
+- Regular cases: Typical inputs that the function is expected to handle.
+- Edge cases: Inputs that are at the boundary of what the function should handle.
+- Error cases: Inputs that should raise exception due to invalid input.
+
+Created on: January 6, 2025
+@author: Melat Assefa
+"""
+
+import unittest
+from solutions.add_numbers import add_numbers
+
+
+class TestAddNumbers(unittest.TestCase):
+    """Unit tests for the add_numbers function."""
+
+    # Regular Cases
+    def test_positive_numbers(self):
+        """Test adding two positive numbers."""
+        self.assertEqual(add_numbers(2, 3), 5)
+
+    def test_negative_numbers(self):
+        """Test adding two negative numbers."""
+        self.assertEqual(add_numbers(-2, -3), -5)
+
+    def test_mixed_sign_numbers(self):
+        """Test adding a positive and a negative number."""
+        self.assertEqual(add_numbers(-1, 1), 0)
+
+    def test_floats(self):
+        """Test adding two floating-point numbers."""
+        self.assertEqual(add_numbers(0.5, 0.5), 1.0)
+
+    # Edge Cases
+    def test_add_zero_to_number(self):
+        """Test adding zero to a number."""
+        self.assertEqual(add_numbers(0, 5), 5)
+
+    def test_add_number_to_zero(self):
+        """Test adding a number to zero."""
+        self.assertEqual(add_numbers(5, 0), 5)
+
+    def test_large_numbers(self):
+        """Test adding very large numbers."""
+        self.assertEqual(add_numbers(1e308, 1e308), 2e308)
+
+    # Defensive Cases
+    def test_type_error_with_string_first(self):
+        """Test that a TypeError is raised for non-numeric input as first argument."""
+        with self.assertRaises(TypeError):
+            add_numbers("a", 1)
+
+    def test_type_error_with_string_second(self):
+        """Test that a TypeError is raised for non-numeric input as second argument."""
+        with self.assertRaises(TypeError):
+            add_numbers(1, "b")
+
+
+if __name__ == "__main__":
+    unittest.main()