conversations.from: human
conversations.value: This math problem has got me stumped: Tom cannot afford a normal doctor, so he goes to a discount clinic that is 70% cheaper.   It takes two visits, though, instead of 1.   A normal doctor charges $200 for a visit.   How much money does he save?
  Can you show me the way?
conversations.from: assistant
conversations.value: Each of Tom's visits was 200*.7=$140 cheaper
  So he paid $200 - $140 = $60 per visit
  That means he paid $60 * 2 = $120
  So he saved $200 - $120 = $80