Empirical evidence suggests that working memory (WM) is closely related to arithmetic performance. WM, which is the ability to monitor and update recent information, underlies various cognitive processes and behaviors including planning, self-regulation, and self-control. However, only a few studies have examined whether WM uniquely explains variance in arithmetic performance when other WM-related domain-general factors are taken into account. In this study, we examined whether WM explains unique variance in arithmetic performance when planning, self-regulation, and self-control are considered as well. We used the Tower of London task as a measure of planning, selfrated reports as a measure of self-regulation and self-control, and WM measures, to test which of these domain-general functions predicts complex multiplication performance. Results showed that planning predicted multiplication accuracy and self-control predicted response time, while WM and self-regulation did not predict complex multiplication performance. Although WM was not a direct predictor of multiplication performance, it possibly exerted its influence as part of planning ability. We suggest that complex multiplication is not predicted by WM per se, but rather by WM-related general cognitive and behavioral factors, namely self-control and the planning component of executive functions.Keywords: arithmetic performance, multiplication, executive functions, planning, working memory, self-regulation, self-control Journal of Numerical Cognition, 2017, Vol. 3(2), 441-467, doi:10.5964/jnc.v3i2.61 Received: 2016-06-06. Accepted: 2017-03-02. Published (VoR): 2017-12-22.Handling Editors: Silke Goebel, University of York, York, United Kingdom; André Knops, Humboldt-Universität Berlin, Berlin, Germany *Corresponding author at: University of Tübingen, Schleichstr. 4, 72076 Tübingen, Germany. E-mail: parvin.nemati@uni-tuebingen.de This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License, CC BY 4.0 (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.People use numerical skills in their everyday life in various situations such as shopping or paying bills at restaurants. About 20% of adults do not achieve basic levels of mathematic competence required for these life skills (Williams, 2003). This mathematical incompetence leads to lower income and less financial security in life (Butterworth, Varma, & Laurillard, 2011;Parsons & Bynner, 2005). Therefore, it is worthwhile to examine the factors that can lead to this incompetence. Two groups of factors that influence mathematical skills have been described in the literature. One group consists of domain-specific factors, such as the approximate number system (e.g., Libertus, Feigenson, & Halberda, 2011; for review see Dietrich, Huber, & Nuerk, 2015) or spatialnumerical associations (e.g., Siegler & Opfer, 2003; but see Cipor...