This paper summarizes an action research project to develop a math screening instrument that would be effective (valid and reliable) and efficient (time for administration). An instrument was developed after review of the mathematics assessment and mathematics disabilities literature. The instrument was administered to kindergarten, first, and second graders during the 2009-2010 school year. Screening data was compared to both teacher rankings and end-of-the-year achievement tests. Correlations ranged from 0.54 to 0.89 and were statistically significant (p less than 0.05). Average administration time ranged from 17.5 minutes (kindergarten) to 11 minutes (second grade). Copies of the instruments are included in the appendix. Preliminary results are positive for further validity and reliability study. A bibliography is provided. (Contains 2 tables.)