title: How to subtract a variable from another variable in python
body: <pre><code>import easygui as eg 
  import sys
  
  version = 'Percentage Calculator'
  
  Options = [ 'Percantage Increase', 'Percentage Decrease' ]
  
  button = eg.buttonbox ('What would you like to calculate', title = version, choices =     Options)
  
  if button == Options [0]:
      enter = eg.enterbox ('Please enter a number between 0 and 999.', title = version,     strip=False)
      if enter &lt; '0' or enter &gt; '999':
              eg.msgbox ('please choose a number between 0 and 999.', title = version,     ok_button='OK')
              sys.exit()
      enter2 = eg.enterbox ('please enter a number between 0 and 999, that is bigger than     the first number.', title = version, strip=False)
      if enter2 &lt; '0' or enter2 &gt; '999':
              eg.msgbox ('please choose a number between 0 and 999.', title = version,     ok_button='OK')
              sys.exit()
      elif enter2 &lt; var enter:
              eg.msgbox ('please choose a number bigger than the first number.', title =     version, ok_button='OK')
              sys.exit()
      Subtract = enter2 - enter
      print (Subtract)
  </code></pre>
  
  <p>this is my code... as you can see, near the bottom, it says 'enter2 - enter' i want this to subtract the second number that the user put in from the first number but it just says...</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Users\olitr_000\Desktop\PYTHON\Percentage Calculator\Percentage     Calculator.py", line 22, in &lt;module&gt;
      Subtract = enter2 - enter
  TypeError: unsupported operand type(s) for -: 'str' and 'str'
  </code></pre>
  
  <p>what can i do so that say enter 1 equals 55 and enter2 = 198 how would i get it so that it does 198 - 55?!</p>
  
  <p>please help, i you need any more information please notify me.</p>