Consider the question. Elmo has 3 times as many books as his sister, Laura. Laura has twice as many books as her brother, Stu. If Elmo has 24 books, how many books does Stu have?
If the answer is '4'; explain the reasoning:
Laura has 24 / 3 = 8 books. Stu has 8 / 2 = 4 books.