This article reports the results of a study of grade 2 students 7 - 8 years old) using game technology versus paper/pencil games and the effects of increased use of game technology on assessments. The study found that the students using the game technology had increased performance and that increased use of technology also increased student performance. Shin, N. Sutherland, L. M., Norris, C. A., & Soloway, E. (2012). Effects of game technology on elementary student learning in mathematics. British Journal of Educational Technology, 43(4), 540-560. doi:10.1111/j.1467-8535.2011.01197.x

I do not have access to XtraMath, so I checked out CoolMath Games. This is easy to search to locate a game to practice a concept. Free - students can use at home or school. CoolMath4Kids is specifically for elementary students and is designed as an amusement park of games. Downside of both is that teachers/parents are not able to set goals or track usage.

The study compares students (grade 4) that received traditional instruction to those who received computer assisted instruction (CAI) with traditional instruction for basic math facts. The results show that daily CAI positively effects student math achievement. This study is interesting in that students received 10 minutes of CAI to achieve these results.

The National Foundation for Educational Research (UK) conducted a review of research since 2006. Findings of the study were split on the impact of game-based learning, found positive impact on engagement in the short term, and that no studies looked at their impact on learning and achievement.