This study evaluates the efficacy of a physically-active number learning game for young preschoolers. The intervention adapts Ramani and Siegler’s (Child Develop 79(2):375–394, 2008) successful The Great Race by modifying the mode of play from seated at a table to jumping with two feet on a large game mat. 75 children (mean age: 46 months) in the first year of a 2-year Title I preschool program were assessed in the fall on enumeration, verbal counting, cardinal principle knowledge (CPK), numeral recognition, and magnitude comparisons; children with a strong conceptual understanding of the cardinality principle were screened out (n = 11) of the intervention. 64 children were randomly assigned to the jumping game, the original seated game, or to a no-intervention control group. For the intervention, children met with an experimenter for four, 15–20-min sessions over a 3-week period and post-intervention assessments were completed 1 week later. All children completed a year-end assessment 5 months after the post-intervention assessment. Of the 64 children in the intervention group, 51 had complete data from all three time points. Repeated measures ANOVA and chi-square tests assessed the effectiveness of the intervention on children’s number knowledge and skills; models tested for the main effects of time and group and the interaction of time*group. Although all numeracy measures showed significant improvement over time, no differences between groups over time emerged. The absence of intervention effects is discussed in the context of intentionally aligning children’s number skills and knowledge with teacher practices and recent early numeracy interventions that target counting and set labelling. (author abstract)