The causal role of numerical and non-numerical order processing abilities in the early development of mathematics skills: evidence from an intervention study

Understanding the basis of mathematical development is essential for supporting mathematics learning and to develop efficient interventions for remediating early problems. In the past decade, evidence has accumulated in support of the importance of ordering skills (i.e., tasks that tap into children's ability to recall the order of items or to judge the correctness of the order of items) in predicting early mathematics performance. Nevertheless, so far these studies have only provided correlational evidence, and intervention studies are lacking. The aim of the current study was to fill this gap by investigating the potential causal role of three types of ordering abilities (number ordering, daily event ordering and order working memory) in the development of mathematics skills during the first year of primary school. Children participated in six brief training sessions over a three-week period, and their mathematics skills and mathematics anxiety were measured before and after the training. In addition to the three training conditions, an active control group was also involved, with children completing reading comprehension exercises. Our findings showed that children's performance improved substantially on all ordering tasks as a result of training. Additionally, training in daily event ordering and number ordering has led to large increases in children's formal mathematics skills. Mathematics anxiety was not affected by the interventions. The current results provide initial evidence for the usefulness of order processing training in developing children's early mathematics skills. They also show that these results are not specific to the domain of numerical ordering.