This paper reports on how the affordances of the app <i>Math Shake </i>reshaped the learning experience - an aspect of a research project examining the ways mobile technologies are used in primary-school mathematics. Students used different digital tools within the app to solve word problems, while the affordances, including multi-representation, dynamic and haptic, made the learning experience different from when using pencil-and-paper technology. However, while the affordances of the MT are important, the teacher’s pedagogical approach was central in the learning.