[racket] Evaluate sub-expression with keyboard shortcut in DrRacket?

Hi!

I'm new to the list and have what may be a silly question:

How do I evaluate a sub-expression within DrRacket's Interactions
window?  I'm coming from Common Lisp/SLIME and Elisp in Emacs and I
reflexively use ctrl-x ctrl-e with the cursor just to the right of the
paren closing the expression I want to evaluate.

For example, I was reading the Guide (excellent!) last night and playing
around and came up with: 

(define (cake amount) (println "Cake is really tasty!"))

Which I know doesn't do anything with amount yet, but the idea was to
test to see if println was a valid function in Racket.  So I wanted to
just evaluate:

(println "Cake is really tasty!")

without copying-and-pasting it to it's own line or anything, before
continuing with my experiments with arguments, error messages when you
don't have any arguments and concatenation.

Does this question make sense? This seems like it'd be really useful
when developing multi-line functions or something. Maybe I just need to
dust off my Emacs skills.  But having DrRacket support these kinds of
muscle-memory out of the box will probably decrease the friction to new
users thinking about adopting Racket.

Two and a half cents,
Nick