Early math instruction is the subject of increasing attention by early childhood researchers. There is evidence to suggest that early math skills are highly predictive of later academic achievement but that there are disparities in early math skills among young children. The purpose of this study was to examine the effectiveness of a systematic instructional procedure on early math skills with two preschoolers who were at risk for math delays. Target math skills were selected based on the individual needs of each child and included sorting, patterning, and shape manipulation. The instructional procedure was effective for helping two children acquire early math skills, with a functional relation demonstrated for each participant. There were mixed results for generalization and maintenance. Contributions to the literature, limitations, and implications for research and practice are discussed. (author abstract)