The Characteristics Of Children's Computational Estimation With Mathematical Learning Disability

Since Carpenter et al. (1980) discovered that students were lacked of basic skills aboutcomputational estimation to adapt to the necessity of practical life in 1980s, the vigorousmass of researches had appeared for computational estimation. Computational estimationadapts to the change about desire for computation in new times. Introducing computationalestimation into mathematics education relaxes such a dilemma,that is,mathematics isreluctant for student to learn and difficult for teacher to teach. At the same time,it also offersa new perspective for us to reveal the regularity of cognitive development of learningdisability students.This study compared mathematically gifted and mathematically learning disabilitystudents (MD) in solving computational estimation and the things of strategy oncomputational estimation with both experimental and clinical interview methods. The processof computational estimation competence with mathematical learning disability was inquiredand it will accumulate more concrete evidence for the theoretical research of cognitivedevelopment with learning disability and initially fill vacancy on computational estimationwith MD. In this research,it was found that Learning Disability students had the same laws asthe gifted in computational estimation, and also had the special ones. We have concluded theresults as follows:1. Computational estimation competence with Mathematical Learning Disability is ratherpoor. There are not significant differences between whole number and decimal computationalestimation achievement, this means MD are not good at using the character and trait ofdecimal to solve the computational estimation problems and the fractioncomputation achievement is the poorest.2. When it comes to strategies, the efficacy and flexibility of the strategies with MD arerather poor. The strategies of inclining to accurate computation and other error are used morefrequently. Some strategies are used more frequently than others in computational estimationof whole number, that is rounding, rough mental computation and other strategies;rounding,ignoring the decimal part and other strategies are used in computational estimation of decimal;changing fraction to another fraction easier to work with, other strategies and regarding digitas arithmetic unit "1" are used in computational estimation of fraction. It is easier for MD tomake mistake in blind guess, algorithm executing error, decimal place error and place valueerror.3. On the mathematical confidence and emotion identification of computationalestimation dimensions, the achievement of MD is rather inactive. But only the emotionidentification of computational estimation is closely related to their achievement ofcomputational estimation.4. The metacognition regulation of computational estimation with MD is rather poor, andthey are not good at regulating their process of computational estimation so that they areeasier to get unreasonable answers. The gender difference with MD is not found under thedifferent level of regulation.