input: Write a function to calculate the average of five numbers entered by a user. Input should be taken from the user and the output should be the average of those numbers.
  
  assert calculate_average([1, 2, 3, 4, 5])==3.0
  assert calculate_average([10, 20, 30, 40, 50])==30.0
  assert calculate_average([0, 0, 0, 0, 0])==0.0
  assert calculate_average([-1, -2, -3, -4, -5])==-3.0
  assert calculate_average([100, 200, 300, 400, 500])==300.0
output: def calculate_average(numbers):
      return sum(numbers) / len(numbers)