diff --git a/Week04/functions_mehmet_balci.py b/Week04/functions_mehmet_balci.py
new file mode 100644
index 00000000..d66a1ce8
--- /dev/null
+++ b/Week04/functions_mehmet_balci.py
@@ -0,0 +1,52 @@
+# A lambda function that calculates x raised to the power of e
+# x is positional-only (must be given by position)
+# e can be given as positional or keyword
+custom_power = lambda x=0, /, e=1: x ** e
+
+
+def custom_equation(x: int = 0, y: int = 0, /, a: int = 1, b: int = 1, *, c: int = 1) -> float:
+    """
+    Calculates the mathematical equation.
+
+    :param x: The first base value.
+    :param y: The second base value.
+    :param a: The exponent for x.
+    :param b: The exponent for y.
+    :param c: The divisor.
+    :return: The result of the equation.
+    """
+
+    # Type checking to ensure all inputs are integers
+    # This is required because tests expect TypeError for invalid types
+    if not isinstance(x, int):
+        raise TypeError("x must be int")
+    if not isinstance(y, int):
+        raise TypeError("y must be int")
+    if not isinstance(a, int):
+        raise TypeError("a must be int")
+    if not isinstance(b, int):
+        raise TypeError("b must be int")
+    if not isinstance(c, int):
+        raise TypeError("c must be int")
+
+    # Perform the calculation: (x^a + y^b) / c
+    return (x ** a + y ** b) / c
+
+
+def fn_w_counter() -> (int, dict[str, int]):
+    # Check if the function already has a counter attribute
+    # If not, initialize it
+    if not hasattr(fn_w_counter, "_count"):
+        fn_w_counter._count = 0
+
+    # Increment the counter each time the function is called
+    fn_w_counter._count += 1
+
+    # Get the module name (without package path if exists)
+    # This ensures it matches the test expectation
+    module_name = __name__.split(".")[-1]
+
+    # Return a tuple:
+    # 1. current call count
+    # 2. dictionary with module name as key and count as value
+    return fn_w_counter._count, {module_name: fn_w_counter._count}