Task Switching Affects Elementary School Children' Age-Related Differences In Arithmetic Strategy Use

Strategy use level is a key indicator of cognitive flexibility. In recent years, arithmetic strategy use has gradually become the focus of mathematics cognitive development research. Numerous studies focused on children' s strategy use in addition and subtraction. Results show that both adults and children could flexibly utilize a variety of strategies to solve arithmetic tasks based on task characteristics and disposal of different strategies. Miyake et al. using the latent variable analysis techniques divided central executive into inhibitory control, task switching and working memory updating, since then more and more researchers began to study the effect of central executive function composition on strategy use. As the main aspect of the central executive function and a basic phenomenon of human cognitive processing, task switching has significant impacts on individuals' arithmetic strategy, which needs to be in-depth study. Researchers found that children's ability to select strategies on mental arithmetic and computational estimation problems is enhanced with age. Therefore, it is helpful further to understand children' s age-related differences in arithmetic strategy use to research different age groups completed complex arithmetic tasks under different switching conditions.In this study, we combined choice/ no-choice method and switching paradigm to examine the impact of task switching on strategy use by setting up three task context(no-switching, switching: numerical comparison / color comparison). Second grade, fourth grade and sixth grade students participated in the study. By comparing three groups' performance, we further revealed age-related differences in arithmetic strategy use influenced by task switching. The main results are as follows:(1) With age, the children' s arithmetic strategies use showed a rise tendency as a whole. Sixth grade is better than fourth grade, and fourth grade is better than the second grade.(2) Task switching affected primary school children' s mental arithmetic strategy distribution, but did not affect the computational estimation strategy distribution.(3) Task switching influenced pupils' mental arithmetic strategy execution, and the effect was different in age. Children's strategy execution performance under the no-switching is better than the switching condition, no difference between the two switching conditions. And sixth grade fastest, followed by the fourth grade, and finally the second grade in each condition. On accuracy, there was no significant difference among three groups in the no-switching condition, however, the correct rate of second grade children' s mental arithmetic strategy execution was significantly lower than that of grade four, six; grade four and six, no significant difference.(4) Task switching influenced children' s computational estimation strategy execution, and the effect is different in age. Children' s strategy execution performance under the no-switching is better than the switching condition, the numerical comparison is slower than the color comparison, and the accuracy was better than the latter. Furthermore, execution speed of these three groups increased with age, the accuracy of grade six was significantly higher than the grade two and four. There was no significant difference between second and fourth grade.(5) For mental arithmetic task, students performed the full decomposition strategy faster in the no-switching condition than switching condition. And they performed the partial decomposition strategy more accurately in the no-switching and numerical comparison condition than in the color condition.(6) For computational estimation task, the speed of executing rounding-down strategy was quicker than rounding-up strategy in all conditions. Children executed strategies accurately, however, they executed rounding-down strategy more accurately than rounding-up strategy in the switching condition. The effect was also diverse in age. In the no-switching condition, grade six students executed the two strategies accurately than grade two, no difference between fourth and sixth grade; in the color comparison condition, grade six students executed the two strategies accurately than grade two and four, no difference between second and fourth grade; in the size comparison condition, grade six students only executed rounding-up strategy accurately than grade four, grade four was better than grade two.(7) Children' s strategy selection reactions of mental arithmetic were affected by task switching. Their performance in the switching condition was significantly slower than in the no-switching condition, and this effect was different in age. For second grade, their performance in numerical comparison condition is much slower than in the no-switching condition, and for fourth grade and sixth grade. There was no obvious difference between the no-switching and switching conditions.(8) Children' s strategy selection accuracy of mental arithmetic was affected by task switching, their performance in the no-switching condition was equal to the performance in the numerical comparison, significantly better than in the color comparison condition, no age difference.(9) Task switching influenced children' s computational estimation strategy choice both on the reaction and accuracy, there was no age difference.(10) Children' s adaptability of strategy choice in different groups will not change within task switching.