diff --git a/calculator/main.py b/calculator/main.py
index 43bf23b..faf1baf 100644
--- a/calculator/main.py
+++ b/calculator/main.py
@@ -2,20 +2,22 @@
 # Performs basic arithmetic operations based on user input
 
 def add(a, b):
-    # TODO: Return sum of a and b
+    return a + b
     pass
 
 def subtract(a, b):
-    # TODO: Return difference of a and b
+    return a - b
     pass
 
 def multiply(a, b):
-    # TODO: Return product of a and b
+    return a * b
     pass
 
 def divide(a, b):
-    # TODO: Return quotient of a and b
-    # Handle division by zero
+    if b == 0:
+        return "Error: division by 0"
+    else:
+        return a/b
     pass
 
 def main():
@@ -27,7 +29,18 @@ def main():
         operator = input("Enter operator: ")
         num2 = float(input("Enter second number: "))
 
-        # Match the operator with the correct function
+        if operator == "+":
+            answer = add(num1, num2)
+        elif operator == "-":
+            answer = subtract(num1, num2)
+        elif operator == "*":
+            answer = multiply(num1, num2)
+        elif operator == "/":
+            answer = divide(num1, num2)
+        else:
+            answer = "Error: invalid operator"
+
+        print("Answer: ", answer)
 
     except ValueError:
         print("Invalid number entered.")
diff --git a/convert-distance/main.py b/convert-distance/main.py
index f6bcfe8..3bbd95d 100644
--- a/convert-distance/main.py
+++ b/convert-distance/main.py
@@ -2,15 +2,18 @@
 # Convert between kilometers, meters, and centimeters
 
 def km_to_m(km):
-    # TODO: Convert kilometers to meters
+    m = km * 1000
+    print("km = ", m, "m")
     pass
 
 def m_to_cm(m):
-    # TODO: Convert meters to centimeters
+    cm = m * 100
+    print("m = ", cm, "cm")
     pass
 
 def cm_to_km(cm):
-    # TODO: Convert centimeters to kilometers
+    km = cm / 100000
+    print("cm = ", km, "km")
     pass
 
 def main():
@@ -24,13 +27,13 @@ def main():
 
     if choice == "1":
         km = float(input("Enter distance in kilometers: "))
-        # Call conversion function
+        km_to_m(km)
     elif choice == "2":
         m = float(input("Enter distance in meters: "))
-        # Call conversion function
+        m_to_cm(m)
     elif choice == "3":
         cm = float(input("Enter distance in centimeters: "))
-        # Call conversion function
+        cm_to_km(cm)
     else:
         print("Invalid choice!")
 
diff --git a/digital-clock/main.py b/digital-clock/main.py
index 986773e..bb4e62d 100644
--- a/digital-clock/main.py
+++ b/digital-clock/main.py
@@ -5,16 +5,17 @@
 import time
 
 def get_current_time():
-    # TODO: Return the current system time in formatted string
+    return datetime.now().strftime("%H:%M:%S")
     pass
 
 def main():
-    print("Digital Clock - Press Ctrl+C to stop\n")
+    print("Digital Clock - Press Ctrl+C to stop")
     
     try:
         while True:
-            # Get current time and display it
-            # Use time.sleep(1) to update every second
+            current_time = get_current_time()
+            print("\r" + current_time, end="")
+            time.sleep(1)
             pass
     except KeyboardInterrupt:
         print("\nClock stopped.")
diff --git a/pick-color/main.py b/pick-color/main.py
index 4286499..f8d9dd9 100644
--- a/pick-color/main.py
+++ b/pick-color/main.py
@@ -4,16 +4,20 @@
 import random
 
 def get_random_color():
-    # TODO: Return a random color from the list
     colors = ["Red", "Green", "Blue", "Yellow", "Purple", "Orange"]
+    return random.choice(colors)
     pass
 
 def main():
     print("Random Color Picker")
 
-    while True:
-        input("Press Enter to pick a color (or Ctrl+C to quit)...")
-        # Call the random color function and display the result
+    try:
+        while True:
+            input("Press Enter to pick a color (or Ctrl+C to quit)...")
+            color = get_random_color()
+            print("Your color is: ", color)
+    except KeyboardInterrupt:
+        print("Stopped.")
 
 if __name__ == "__main__":
     main()
diff --git a/to-do/main.py b/to-do/main.py
index a1fcc80..7ab18cc 100644
--- a/to-do/main.py
+++ b/to-do/main.py
@@ -9,15 +9,36 @@ def show_menu():
     print("4. Exit")
 
 def add_task(tasks):
-    # TODO: Ask user for a task and append to the list
+    task = input("Enter a new task: ")
+    tasks.append(task)
+    print("Task added.")
     pass
 
 def remove_task(tasks):
-    # TODO: Show task list and allow user to remove by index
+    if len(tasks) == 0:
+        print("No tasks to remove.")
+        pass
+    view_tasks(tasks)
+    try:
+        index = int(input("Enter the task number to remove: "))
+        if 1 <= index <= len(tasks):
+            tasks.pop(index - 1)
+            print("Task removed.")
+        else:
+            print("Invalid task number.")
+    except ValueError:
+        print("Error: please enter a valid number")
     pass
 
 def view_tasks(tasks):
-    # TODO: Display current list of tasks
+    if len(tasks) == 0:
+        print("No tasks added yet.")
+    else:
+        count = 1
+        print(tasks)
+        for task in tasks:
+            print(count, ". ", task)
+            count += 1
     pass
 
 def main():