diff --git a/Week04/functions_zeynepnur_erten.py b/Week04/functions_zeynepnur_erten.py
new file mode 100644
index 00000000..70ce9dd4
--- /dev/null
+++ b/Week04/functions_zeynepnur_erten.py
@@ -0,0 +1,20 @@
+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 is used to calculate a custom equation
+    :param x: first base
+    :param y: second base
+    :param a: exponent for x
+    :param b: exponent for y
+    :param c: divisor
+    :return: the result of equation (x**a + y**b)/c
+    """
+    return float((x**a + y**b)/c)
+
+counter = {}
+def fn_w_counter() -> (int, dict[str, int]):
+    caller = __name__
+    counter[caller] = counter.get(caller,0) + 1
+    return sum(counter.values()), counter
+