To introduce combinations and tree diagrams to my 6th grade:
I showed the following Cyberchase clips
(before having the students play with Mr. Potato Heads, of course.)
If you haven't heard of Cyberchase, it is a PBS show that correlates with state standards.
It is a cartoon TV show where the "Cyberchase Gang"(good guys) try to stop "Hacker" (bad guy) and end up accomplishing this by using math.
It is always followed by a "Real World" three minute clip starring "Harry" or "Bianca" that follows up on the same math idea as the episode.
"Cyberchase" - A Day At the Spa
Disclaimer: Since this is on youtube, the episode is cut into three parts...
you can show all three as a treat, or just the third to cut right to the "math".
1) Starting at the beginning of this clip the "Cyberchase Gang" must use tree diagrams to solve the mystery and find the combination so that they can stop Hacker (the bad guy). (I explain give the set-up to the clip verbally rather than watching the whole episode. At this point in the year, they've seen enough Cyberchase clips to get the gist of the story lines.)
2) Fast-forward to 4minutes and 34seconds and you will see the "For Real" closure to the episode where Harry gets a job working at a sandwich shop and uses the idea of "combinations" to promote the sandwich shop by saying they have 120 combinations to choose from!
I really can't say enough good things about clips from Cyberchase. Hope you like it too!