The Effect Of Material Characteristics On The Middle School Student's Estimates Accuracy

Estimate is a form that the individual answer questions in a rough way without the accurate calculation of premise and only with the original knowledge and experience, which are interaction skills by concept, mental and arithmetic. In 1980s, since Carpenter and his staff discovered that it was difficult for the students who lacked of basic skills about computational estimate to adapt to the necessity of practical life, more relevant researches were made to estimate component, tactics and speed.The domestic study of estimate began in the early 1990s, the research scope involving estimate of speed, accuracy and influence factors of estimation etc. The mainly objects of the study are primary school students, college students and adults. The high school stage is thought as a key period of human thinking pattern transiting from the concrete to the abstract, and the developmental level of the ability to estimate will play a very important role to the individual mathematical ability. Therefore, it is necessary to study the accuracy of the estimate and its influencing factors for people in high school, which would provide some proof support for the development and education to the high school students in estimate ability.This study employs a 4-factor design as:3(experiment type:Senior 1/Senior 2/Senior 3)*2(material form:language questions/numeral questions)*3(number type:whole number/decimal/fraction)*4(operation: add/subtract/multiple/divide)The results are as follows:(1) There are significant differences in accuracy of estimate competence between senior year and middle school students.(2) The accuracy of estimate is affected by Material characteristics.