prompt: Mark has the option of getting a $300 lens with a 20% discount or a $220 lens.  How much money does he save by buying the cheaper lens?
messages.content: Mark has the option of getting a $300 lens with a 20% discount or a $220 lens.  How much money does he save by buying the cheaper lens?
messages.role: user
messages.content: The discount is worth 300*.2=$<<300*.2=60>>60
  So the lens cost 300-60=$<<300-60=240>>240
  That means he saves 240-220=$<<240-220=20>>20 by buying the cheaper lens
  #### 20
messages.role: assistant