diff --git a/solutions/sum_of.py b/solutions/sum_of.py
new file mode 100644
index 000000000..42694ab68
--- /dev/null
+++ b/solutions/sum_of.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on XX XX XX
+
+A module gives a summation of two numbers.
+
+@author: Tagwa Hashim
+"""
+
+
+def sum_of(num1, num2):
+    """
+    Adds two numbers and returns their sum.
+
+    Args:
+        num1: The first number. Can be an integer or a float.
+        num2: The second number. Can be an integer or a float.
+
+    Returns:
+        The sum of num1 and num2.
+
+    Raises:
+        AssertionError: If either num1 or num2 is not a number (int or float).
+
+    Examples:
+        >>> sum_of(3, 5)
+        8
+        >>> sum_of(2.5, 3.7)
+        6.2
+        >>> sum_of("hello", 2.718)
+        Traceback (most recent call last):
+             ...
+        AssertionError: Both arguments must be numbers (int or float).
+    """
+    assert isinstance(num1, (int, float)) and isinstance(num2, (int, float)), (
+        "Both arguments must be numbers (int or float)."
+    )
+    return num1 + num2
diff --git a/solutions/tests/test_sum_of.py b/solutions/tests/test_sum_of.py
new file mode 100644
index 000000000..c8563b6e3
--- /dev/null
+++ b/solutions/tests/test_sum_of.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Unit tests for the sum_of function.
+
+@author: Tagwa Hashim
+"""
+
+import unittest
+
+from solutions.sum_of import sum_of
+
+
+class TestSumOf(unittest.TestCase):
+    """Test the sum_of function"""
+
+    def test_add_integers(self):
+        """Test sum_of of two integers."""
+        self.assertEqual(sum_of(7, 12), 19)
+
+    def test_add_floats(self):
+        """Test sum_of of two floats."""
+        self.assertEqual(sum_of(1.6, 3.3), 4.9)
+
+    def test_add_mixtype(self):
+        """Test sum_of of integer and float."""
+        self.assertEqual(sum_of(3, 2.05), 5.05)
+
+    def test_add_zero(self):
+        """Test sum_of with zero."""
+        self.assertEqual(sum_of(0, 5), 5)
+        self.assertEqual(sum_of(5, 0), 5)
+
+    def test_add_negative_numbers(self):
+        """Test sum_of with negative numbers."""
+        self.assertEqual(sum_of(-3, -5), -8)
+        self.assertEqual(sum_of(-3, 5), 2)
+
+    def test_invalid_input_type_num(self):
+        """Test with invalid input type for num1 or num2, should raise assertion error"""
+
+        with self.assertRaises(AssertionError):
+            sum_of("hello", 2)
+            sum_of(18, "hello")
+
+
+if __name__ == "__main__":
+    unittest.main()