For early finishers? Math Workshop Adventures Create a new number each day. When kids finish their math assignments, they work on the number of the day problem. Introduce new concepts as the year progresses (multiplication.
Reading chains: Every time a student finishes a book, they can write their name, title and author of the book on a strip and attach it to their class chain. Perhaps the class with the longest chain at the end of the year could get some type of reward.