From Sue Shellenbarger in October 29 Wall Street Journal:
Game designers are offering some promising new options for elementary and middle-school students. An app called Motion Math: Fractions, is available for Apple and Android devices. Players tilt their devices to direct a falling star to the correct place on a number line, which displays a fraction, percent, decimal or pie shape. Wrong answers generate helpful hints and instruction. Playing the game 20 minutes a day for five days increased fractions knowledge by 15% among 120 elementary-school children, according to a controlled, peer-reviewed study published by GameDesk, Los Angeles, a nonprofit that studies and develops educational games and simulations. Motion Math also offers a fractions game called Motion Math Zoom.