I love using centers and games to learn for all subjects. I tend to trick my kids into playing a game that they have to answer questions in order to play the game :)
When I teach science I prefer hands on experiments using science journals that require the kids to think, predict and record at different stages of the activity.
Math centers work best for my classes. This allows me to work with students individually and allow students to learn independence. I use math journals as well to take notes, record learning, write vocabulary and answer questions with deep thought and work shown.