Calculator for Python 3.7 Made by AB26 (Beginner)

Calculator for Python 3.7
Made by AB26 (Beginner)

start = input("Welcome to your Calculator. In order to begin, please type Start")
if start == "Start":
    number_1 = float(input("Enter the first number"))
    operation = input("Enter the operation which you will be using: *, /, +, -")
    number_2 = float(input("Enter the second number"))

    if operation == "*":
        print(number_1*number_2)
    elif operation == "+":
        print(number_1+number_2)
    elif operation == "/":
        print(number_1/number_2)
    elif operation == "-":
        print(number_1-number_2)
    else : print("Enter a operation which has been stated")
else : print('"Error: You have not written \"Start\"')