The last unit that I do with the trig kids is sequences and series. Now, they find these topics to be incredibly easy by the end of the year because of the level of rigor they've seen throughout the school year. Now, even though some kids find it easy, there are a few who benefit from the practice and plus, I hate allowing them to work on homework.
Here's a speed dating activity for both sequences and series. There are ten cards a piece and practice a variety of topics including evaluating series and finding formulas and specific terms of the sequences.
Enjoy the pretty fonts!
Sequence Task Cards