XP Math has some fun games under the measurement category.  Try the helicopter and the alien spaceship angle games!  I hit 29 on them today.  Then look under geometry and play the coordinate grid game.  There you have an avitar that seeks out the strange creatures on the grid.  Free games with learning at the same time and sound effects that brought the teachers in from the other room!  And…don’t forget chopper math under numbers and operations.  Wow!  Our new computers make it fly fast!