eslHQ - Elementary School Phonics Lesson

Hello everyone! I am teaching at a J.H.S. in Japan and while the students are taking their tests next week, I am being sent to the elementary school next door :doh: I have to teach three classes to the sixth graders. I was told to teach `phonics`. I’ve asked for a narrower topic, like the vowels only, but no one seems to be willing to narrow the view for me. And I haven't figured out what to narrow it to, yet. I’ve never taught a class completely devoted to phonics. I have taught phonics but I prefer to break it up into bite size chunks. So that’s why I’m coming here.

My question are:
1. What phonics should I teach?
2. And how do I fill a 45 minute long class with phonics activities?

Some ideas that I’ve been throwing around is of course BINGO using the initial sound. I was also thinking of introducing some vocabulary (or even better using vocabulary they know) and play something like the flyswatter game, where the cards are on the blackboard and the students slap the card after I say the initial sound.