List one example where Claudia plans and Jamie controls the expenses in "Mixed Up Files of Mrs. Basil E. Frankweiler".
Claudia meticulously plans every detail of their running away. At her direction, she and Jamie board the school bus as usual, then hide in the seats when the bus arrives at school. After they escape detection, they head over to the train station, carrying their carefully packed belongings. Claudia and Jamie arrive at Greenwich station in time to catch the 10:42 local, which they ride to Manhattan, where they will hide out at the Metropolitan Museum of Art (Chapter 2).
Claudia had planned for she and Jamie to take a taxi from the train to the museum, but Jamie, acting as treasurer, vetoes that idea. He points out that they have no income, and must make the money they have last as long as they can. Claudia accepts his argument, and says that they can take a bus, because it is cheaper. Jamie vetoes that idea as well, noting that a bus would still use up forty cents of their money, and decides that they will walk instead (Chapter 3).
Claudia has a strong sense of organization and planning, and Jamie has a good head for finances. The two of them make a good team in their adventure of running away.