Arcademics
Arcademics: Canoe Puppies
Canoe Puppies is a multiplayer math game that allows students from anywhere in the world to race against each other while practicing adding two-digit numbers!
National Council of Teachers of Mathematics
The Math Forum: Lesson Plans: Fractions
Teachers, this is the place to come for fraction lesson plans if you teach elementary students. All the topics have a number of resources available from which to choose.