This study examined the extent to which the iPad app, Spatial Temporal Mathematics (ST Math), diminished college remedial mathematics students' natural number bias and deepened their fraction conceptual understanding. In this quasi-experimental study one class played the ST Math fraction games for 8 weeks, and they were compared to a control class who were taught without technology. The frameworks for this study included the framework theory of conceptual change, the reorganization theory, the microworld and the Lesh Translation Model. Pre and post- tests were used to examine the fraction conceptual understanding of the students in the ST Math class and the non-ST Math class before and after the intervention. Also, interviews were conducted to investigate how the ST Math students developed their fraction conceptual understand before and after the game play, compared to the non-ST Math students. As a whole, the students in both classes exhibited the natural number bias in all three areas: magnitude, density, and computation at the pre-test stage. However at the post-test stage, they diminished the bias in magnitude but in the other two areas, the bias was persistent. Overall, the statistical result was not significant between the ST Math class and the non-ST Math class on the post-test. However, the ST Math class had more students who answered correctly regarding the fraction density concept on the post-test. Similarly, the post-interview results revealed that the ST Math students exhibited conceptual gain in fraction magnitude, the fraction addition concept, and the fraction multiplication concept. However, although they showed the conceptual gain in fraction multiplication, they had difficulty with the concept of fraction division. The students in both classes did not show any conceptual gain in fraction division. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]