diff --git a/challenges/01-calc.py b/challenges/01-calc.py
index 87f5190..4a54b21 100644
--- a/challenges/01-calc.py
+++ b/challenges/01-calc.py
@@ -2,3 +2,22 @@
 # input() always returns a string value. If you ever want someone
 # to enter a number you have to use the `int()` function to convert
 # what they typed in to a string.
+
+math = input("What calculation would you like to do? (add, sub, mult, div)")
+
+num_one = input("What is the first number?")
+
+num_two = input("What is the second number?")
+ 
+def do_math(number_one, number_two):
+    if "add" in math:
+       return number_one + number_two
+    elif "sub" in math:
+        return number_one - number_two
+    elif "mult" in math:
+        return number_one * number_two
+    elif "div" in math:
+        return number_one / number_two
+    
+# Output
+print(do_math(int(num_one), int(num_two)))
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diff --git a/challenges/02-reverse.py b/challenges/02-reverse.py
index 8cf2677..6e02518 100644
--- a/challenges/02-reverse.py
+++ b/challenges/02-reverse.py
@@ -6,3 +6,22 @@
 # several ways to reverse a string, and it's a good read!
 #
 # http://www.techbeamers.com/essential-python-tips-tricks-programmers/?utm_source=mybridge&utm_medium=blog&utm_campaign=read_more#tip1
+
+word = input("Enter a word to reverse: ")
+
+def reverse_word(word):
+    drow = ""
+    for letter in reversed(word):
+        drow += letter
+    print(drow)
+    print("".join(reversed(word)))
+
+reverse_word(word)
+
+# python slice syntax (works on lists or strings)
+my_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+# [slice start (default 0): slice end (default end of list): step (default 1)]
+my_list_copy = my_list[::] # make a copy with defaults
+print(my_list[::-1])
+
+print(word[::-1])
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diff --git a/challenges/03-bank.py b/challenges/03-bank.py
index 554cb1d..a40ade7 100644
--- a/challenges/03-bank.py
+++ b/challenges/03-bank.py
@@ -1,3 +1,35 @@
 print("Welcome to Chase bank.")
-print("Have a nice day!")
+balance = 120000
 
+
+def accounting(action, balance):
+    if "deposit" in action:
+        deposit = input("How much would you like to deposit?\n")
+        balance += int(deposit)
+        print(f"Your new balance is {balance}")
+        done = input("Are you done?\n")
+        sign_out(done, balance)
+    elif "withdraw" in action:
+        withdrawl = input("How much would you like to withdrawl?\n")
+        balance -= int(withdrawl)
+        print(f"Your new balance is {balance}")
+        done = input("Are you done?\n")
+        sign_out(done, balance)
+    elif "check_balance" in action:
+        print(f"Your balance is {balance}")
+        done = input("Are you done?\n")
+        sign_out(done, balance)
+
+def sign_out(decision, balance):
+    if "yes" in decision:
+        pass
+    if "no" in decision:
+        action = input("What would you like to do? (deposit, withdraw, check_balance)\n")
+        accounting(action, balance)
+
+
+print(f"Your balance is {balance}");
+action = input("What would you like to do? (deposit, withdraw, check_balance)\n")
+accounting(action, balance)
+
+print("Have a nice day!")
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diff --git a/challenges/04-alphabetical.py b/challenges/04-alphabetical.py
index 5051ec4..90e675a 100644
--- a/challenges/04-alphabetical.py
+++ b/challenges/04-alphabetical.py
@@ -1,3 +1,17 @@
 # You'll need to use a couple of built in functions to alphabetize a string. 
 # Try to avoid looking up the exact answer and look at built in functions for
 # lists and strings instead.
+
+word = input("Enter a word to alphabetize.")
+# sorted function approach
+alpha = ""
+for letters in sorted(word):
+    alpha += letters
+
+print(alpha)
+
+# convert to list approach
+word_list = list(word)
+word_list.sort()
+string = "".join(word_list)
+print(string)
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