This paper describes the procedure of teaching multiplication tables to a female student, who was previously not able to acquire sufficient skills in this regard, even though she had regularly attended school. The intervention consisted of a short, intense training on how to use the Count-By Strategy. A multiple baseline design across three different fact sets (7s, 8s, and 9s) was implemented. Results showed such marked improvements that they even reached statistical significance in a randomization test. Limitations of the study, implications of the findings, as well as future research questions are discussed.