Python 101: Bot with maths functions

# Futurelearn: Python 101 from RPi Foundation - Bot with functions

def totalaverage():
    how_many = input("How many numbers do you have> ")
    how_many = int(how_many)
    total = 0

    for number_count in range(how_many):
        number = input("Enter number " + str(number_count+1) + "> ")
        total = total + int(number)
    if command == "average":
        result = total / how_many
    else:
        result = total
    output = str(result)
    print("The " + command + " of your numbers = " + output)

def do_calculation():
    print("lets " + command + " some numbers")
    input_1 = input("Number 1> ")
    input_2 = input("Number 2> ")
    number_1 = int(input_1)
    number_2 = int(input_2)

    if command == "add" or command == "plus":
        result = number_1 + number_2
        operator = " + "
    elif command == "subtract" or command == "take away":
        result = number_1 - number_2
        operator = " - "
    elif command == "multiply" or command == "times":
        result = number_1 * number_2
        operator = " * "
    elif command == "divide":
        result = number_1 / number_2
        operator = " / "

    output = str(result)
    print(str(input_1) + operator + str(input_2) + " = " + output)

finished = False

while finished == False:
    print("\nHi, I am your personal 'bot' called Dave.")

    command = input("How can I help you? ")

    if command == "add" or command == "plus":
        do_calculation()
    elif command == "subtract" or command == "take away":
        do_calculation()
    elif command == "multiply" or command == "times":
        do_calculation()
    elif command == "divide":
        do_calculation()
    elif command == "average" or command == "total":
        totalaverage()
    elif command == "meal":
        people = int(input("how many people ate a meal> "))
        total = 0

        for meal in range(people):
            cost = float(input("How much was meal " + str(meal+1) + "? "))
            total = total + cost

        print("Each person will need to pay " + str(round(total/people,2)) + " pounds\dollars each.")
    elif command == "bye":
        finished = True
    else:
        print("Sorry I don't understand")