...or at least some video games:

A team of researchers led by Ricardo Rosas (...) studied the effects of integrating handheld video games into the first- and second-grade curriculum for 30 minutes a day. Their study was unique because they designed a teaching game with features similar to commercial video games. In a typical video game, the player must perform several tasks in order to reach a goal. As the game progresses, the tasks get more and more challenging. Players are highly motivated to learn the new tasks because it helps them reach the game’s ultimate goal.

Rosas et al. realized that in order for students to be motivated to play the games, the “goal” of the game can’t be something like “learn to read one-syllable words.” Instead, they designed games with goals like “saving the fairies imprisoned in the temples of the city.” From the child’s perspective, it just happened that in order to save the fairies, one of things you had to learn was how to read one-syllable words, such as “sol” for “sun.”

...from Cognitive Daily