day 21 fixes

.gitignore

@@ -7,4 +7,6 @@ res.py
 hello.py
 backup.md
 .DS_Store
-__pycache__
+__pycache__
+playground/
+playground

mypackage/arithmetics.py

@@ -0,0 +1,28 @@
+def add_numbers(*args):
+    total = 0
+    for num in args:
+        total += num
+    return total
+
+
+def subtract(a, b):
+    return (a - b)
+
+
+def multiple(a, b):
+    return a * b
+
+
+def division(a, b):
+    return a / b
+
+
+def remainder(a, b):
+    return a % b
+
+
+def power(a, b):
+    return a ** b
+
+
+

mypackage/greet.py

@@ -0,0 +1,2 @@
+def greet_person(firstname, lastname):
+    return f'{firstname} {lastname}, welcome to 30DaysOfPython Challenge!'