Developing a Model based on Constructivism Approavh for Teaching Simplification of Algebraic Expressions in the 8th Grade

The aim of the present study was developing a model based on constructivism approach, for teaching simplification of algebraic expressions in the 8th Grade. Mixed method proved to be suitable for the study. At the first phase, a primitive model was designed and a focus group was formed consisting of 15 volunteer mathematics teachers of the same grade and they met three times until the model was modified and validated for implementation. At the second phase, an experimental study was designed involving 60 Grade 8 students that randomely selected and assigned to two experimental and control groups. After taking the pre-test, the control group was taught as usual and the experimental group was taught using the developed model as treatment. At the end, a post- test was carried out for both groups. The results showed that the difference between two groups was statistically significant in the favor of the experimental group that indicates that posivie effectiveness of the developed model on the students’ performance in Grade 8.