Study On Improving The Students Calculating Ability In Compulsory Education

Estimation falls into the category of non-accurate calculation. Its importance in mathematic education has long been neglected. However, estimation is a widely used mathematics-based computing method as well as behavior in people's daily life, work and study. Under circumstances where accurate computation or judgment is unnecessary or impossible, estimation comes in. As an important mathematical approach and ability, estimation has been given increasingly greater attention in recent years, as it effectively combines practical problems with mathematical theories and thus meets the new demand on computing techniques posed by our modern times. The national criteria for the new curriculum of the nine-year compulsory education stipulate,"Importance should be attached to oral arithmetic, advancement made in estimation and encouragement given to efforts in varying calculation methods and avoiding complicated computation procedures."As a way of coming up with a possible result based on the given information, estimation enables students to make reasonable predictions and inferences independently according to the mathematical data gathered from the problem-solving situation. Estimation has already occupied a key position in the curricula of primary and middle schools'mathematic education.Mathematical estimation is by nature an inclination to solve problems by way of mathematical calculation. It is a way of processing data through quick yet reliable observation, comparison, inference and reasoning in accordance with sound mathematic rules. The ability to estimate reflects a high-level mathematical proficiency derived from a profound understanding of the relations between different components of the mathematical problem. With the help of estimation, such goals as making judgment, distinction and exploration, and orientation and optimization can be achieved without difficulty.This paper analyzes, in a systematic way, the curricular content and current situation in the teaching of estimation methods as part of the mathematical education in China's nine-year compulsory education system; classifies the estimation-related problem types in the textbooks of different grades; pins down the major characteristics of lesson organization and limitations in the teaching of estimation; and offers a number of strategies to deal with the problems in the teaching of estimation. The author of this paper points out that all the discussions concerning the teaching of estimation in the phase of China's nine-year compulsory education boil down to two crucial questions:"Why is estimation necessary?"and"How can reasonable estimation be made?"In response to these two questions, all mathematical educationists should do their best in establishing a conceptual framework which acknowledges the importance of estimation and provides methods in conducting sound estimation, drawing on their own personal experiences in teaching.