conversations.from: human
conversations.value: Donny saves $15 on Monday, $28 on Tuesday and $13 on Wednesday. On Thursday he spends half of his total savings so far. How much did he spend?
conversations.from: assistant
conversations.value: Donny saves a total of $15+$28+$13 = $56 across all 3 days
  He spends half of his total savings which is $56*(1/2) = $28