Many children in the U.S., particularly those from low socioeconomic status (SES) backgrounds, do not develop sufficient math skills to be competitive in today's technological world. We utilized a mediation/moderation framework and the ECLS-K dataset to investigate factors that can decrease the SES-related math achievement gap in kindergarten. Starting kindergarten proficient in math and experiencing a supportive home learning environment significantly decreased SES achievement differences. Proficiency in math at the start of kindergarten accounted for the greatest decrease in the SES-math achievement gap. Findings support the importance of comprehensive and multi-contextual approaches targeted to families and schools for improving children's exposure to math-relevant experiences. (author abstract)