title: TypeError in calculations with user-input values
body: <p>I realize this has been answered but Im a super noob. I know it has to do with male/female being a string but I thought I had it defined? How can I get the calculation to work?</p>
  
  <pre><code>num = int(input('Please enter number of standard drinks consumed:'))
  while num &lt;= 0:
      print ('Error: The number cannot be negative or zero.')
      num = int(input('Please enter number of standard drinks consumed:'))
  weight = int(input('Please enter weight in pounds:'))
  while weight &lt;= 0:
      print ('Error: The weight cannot be negative or zero.')
      weight = int(input('Please enter weight in pounds:'))
  time = int(input('Please enter number of hours since first drink:'))
  while time &lt;= 0:
      print ('Error: The time cannot be negative or zero.')
      time = int(input('Please enter number of hours since first drink:'))
  gender = input('Please enter the sex male or female:')
  male = 0.68
  female = 0.55
  
  
  B = -0.015 * time(2.84 * num / weight * gender)
  print ('The BAC is', format(B, ',.2f'))
  </code></pre>