Development Of Mental Addition Ability And Mental Subtraction Ability From First Graders To Fourth Graders In Elementary School

Mental arithmetic is an important ability. How to master the mental arithmetic attracts much attention from educators. Researches attached more and more importance to the relationship between mental arithmetic development and working memory.The development of pupils' mental arithmetic was studied in this article. An addition and subtract ability testing system was developed. 160 primary school students took part in the mental arithmetic experiment. The experiment investigated the latency and result of mental addition and subtraction. The results showed:1. The accuracies and speeds of mental arithmetic of pupils increased with the growth of subject's grades. The increase was not linear. Increasing amplitudes of different grades were different. Increasing amplitude between first and second was higher than others.2. The correlation of latencies and errors were significant in the first students.3. There was no significant gender difference.4. The correlations of latencies and errors were significant between addition and subtraction. There was significant difference between addition and subtraction in the first students, but there was not significant in the other graders. In the first students, both the mean of latencies and the mean of errors of subtraction were obviously higher than of addition.5. In cording to the latencies, addition facts and subtraction facts were clustered. There was significant different on the latencies between the different bundles. It was maybe related with strategy used on mental arithmetic.