Since the outbreak of COVID-19 schools have gone into lockdown and teachers have had to teach pupils online from home. When pupils go back to school, standard, contemporary learning methods do not seem to be enough to reduce incurred hiatuses. Social robots are slowly becoming an integral component of our society and have great potential as educational technology. This study explores how social robots in classrooms can contribute to reducing mathematics-related hiatuses in Dutch primary education (pupils from four till twelve years old). A social robot as a tutor is evaluated by means of a field study with children (n = 43) to compare a class working with the robot, to a class working without the robot. Multiple factors on learning effect are taken into account by using a survey. Our results demonstrate that a robot can take the role of a tutor and practice with pupils. The results are of interest to researchers in the field of human-robot interaction as well as to educational institutes who wish to understand the implications of adopting robots in education.