diff --git a/Week04/functions_feyza_ozdemir.py b/Week04/functions_feyza_ozdemir.py
new file mode 100644
index 00000000..9bea792b
--- /dev/null
+++ b/Week04/functions_feyza_ozdemir.py
@@ -0,0 +1,51 @@
+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:
+    """
+    This function calculates the result of a custom mathematical equation.
+
+    :param x: The first base value (positional-only), defaults to 0.
+    :type x: int
+    :param y: The second base value (positional-only), defaults to 0.
+    :type y: int
+    :param a: The first exponent (positional-or-keyword), defaults to 1.
+    :type a: int
+    :param b: The second exponent (positional-or-keyword), defaults to 1.
+    :type b: int
+    :param c: The divisor (keyword-only), defaults to 1.
+    :type c: int
+    :return: The result of (x**a + y**b) / c as a float.
+    :rtype: float
+    """
+    if not (type(x) is int and type(y) is int and type(a) is int and type(b) is int and type(c) is int):
+        raise TypeError("All parameters must be integers.")
+    
+    return float((x ** a + y ** b) / c)
+
+
+def fn_w_counter() -> (int, dict[str, int]):
+    """
+    This function counts total function calls and tracks calls per caller module.
+
+    :return: The total call count and a dictionary of caller counts.
+    :rtype: (int, dict[str, int])
+    """
+    caller = __name__
+
+    fn_w_counter.total_calls += 1
+    fn_w_counter.caller_counts[caller] = fn_w_counter.caller_counts.get(caller, 0) + 1
+
+    return fn_w_counter.total_calls, dict(fn_w_counter.caller_counts)
+
+
+fn_w_counter.total_calls = 0
+fn_w_counter.caller_counts = {}
\ No newline at end of file