add square, cube, and square_n_times functions

Author: Eman Muamar

calculator.py

@@ -15,4 +15,19 @@ def divide(a, b):
 
 print("I'm going use the calculator functions to multiply 5 and 6")
 x = multiply(5,6)
-print(x)
+print(x)
+
+def square(x):
+    return x ** 2
+
+
+def cube(x):
+    return x ** 3
+
+
+def square_n_times(number, n):
+    total = 0
+    for _ in range(n):
+        total += number ** 2
+    return total
+