conversations.from: human
conversations.value: Susan earned $600 from babysitting over the summer. She went shopping and spent half of it on clothes. Then she spent half of what was left on books. How much money did she have left?
  Work out the solution step by step.
conversations.from: assistant
conversations.value: Susan spent 600/2=300 on clothes
  After buying clothes she had 600-300= 300 dollars left
  She spent 300/2=150 dollars on books
  She had 300-150=150 dollars left