There is now a large body of evidence indicating that executive functions, in particular working memory, are related to mathematics proficiency in both children and adults. To date however, this basic knowledge has not been effectively exploited in the classroom because our understanding is not detailed enough. In this talk I will present recent research investigating the relationship between mathematics proficiency and executive functions in greater depth. I will report data from projects investigating the role of executive functions in knowledge of arithmetical facts, procedures and concepts, as well as advanced mathematics. I will also explore the training and transfer of executive functions across domains. Implications for both the researcher and classroom teacher will be discussed.