conversations.from: human
conversations.value: Break down this math problem: Five coaster vans are used to transport students for their field trip. Each van carries 28 students, 60 of which are boys. How many are girls?
conversations.from: assistant
conversations.value: There are a total of 5 vans x 28 students = 140 students.
  If 60 are boys, then 140 - 60 = 80 of these students are girls.