Studies On The Development And The Mechanism Of Mental Arithmetic In Children And Adolescents

As an important thinking activity in the ordinary life, mental arithmetic is also one of the main subjects in cognitive development. This research was intended to solve two problems, one involving how the mental arithmetic capacity improved in children and adolescents, the other concerning the mechanism of mental arithmetic with age changing. Processing speed and working memory are two essential elements in the process of mental arithmetic, which are regarded as the mediations to account for the age-related influences in cognition. A sample of 248 children and adolescents of 10 to 18 years of age and a battery tests of processing speed, working memory, mental arithmetic tests was conducted to analyze the roles of processing speed and working memory in the developmental process of mental arithmetic. The results indicate:1. The cognitive capacities such as processing speed, working memory and mental arithmetic have increased with the age increment during childhood and adolescence.2. Reaction time and errors generally decreased with the advance of age, but the magnitude of age differences in mental arithmetic was significantly reduced by statistically controlling measures of processing speed and working memory.3. Processing speed and working memory play critical role in age differences in mental arithmetic. The contribution of processing speed to mental arithmetic in the development was about 43%-76%, comparing with the contribution of working memory, 36%-68%.4. The total contribution of processing speed and working memory to mental arithmetic in development was about 53%-86%.5. Perceptual speed has more influences on the age differences in mental arithmetic than sensorimotor speed.6. Digit working memory has more effect than visuospatial working memory.