If math is about measurement, then Mathletics may have your child's number. Much like games that post the best scores of players, the Mathletics SOAP API makes student scores accessible to programs as well as its website.
Offering a full curriculum for kindergarten thru grade 12, cost starts at $59/per year per student, with discounts for larger numbers of subscribers. Includes free support. Matletics Hall of Fame isn't just used by parents--schools like it as well, as Ms. D. Maresch, a Second Grade Teacher at Saint Elizabeth School in Pennsylvania attests,
"Mathletics is a wonderful program for the students I teach. They are so very elated to work on Mathletics, that when they come in the classroom in the morning the first question I get is are we going to the lab so we can work with the Mathletics. They are trying to win the different awards which I print off when they earn them. It is a wonderful program."
Mathletics is international in reach, tailoring its curricula to 17 different countries. Pedagogically, they are on to something, reporting that "99.2% of students who attempt an activity three times will achieve mastery. This normally takes less than 20 minutes." In other words, repetition goes hand in hand with mastery.