Children with autism spectrum disorder (ASD) have difficulty generalizing from directly trained responses to untrained responses (i.e., emergent responding). In this study, we used a chain prompt combined with matrix training to teach 2 participants with ASD to tact 192 three-digit numerals. We used a multiple-baseline design across matrices to evaluate the treatment effects on trained and untrained tacts of numerals. Both participants mastered all numerals exposed to training and all numerals not exposed to training after 3 to 5 sixteen-trial sessions per matrix. One participant learned to tact 8 numerals for each 1 numeral exposed to direct training, and the other participant learned to tact 12 numerals for each 1 numeral exposed to direct training. We discuss these results relative to the effectiveness and efficiency of our chain prompt combined with matrix training for teaching tacting skills for targets with shared stimulus properties that facilitate generalization to untrained targets.