Erm...
Blend them in a belnder into a nice, nutritious, healthy drink?
Other than that...
Graphs! If you're looking at something like GDP or whatever as it changes over time, try plotting it as a graph. If like me you've a bit of a visual memory you'll be able to recall it much better.
Flashcards work in a similar way, especially for things like teh state of the economy at a certain date.
Hope that helps!