Development of Connecting Extending Review (CER) Learning Model to Improve Student’s Mathematical Reasoning Ability

This study is a research & development, learning model of connection, extending, review (CER). The steps in this consist three steps, those are: (1) preliminary including literature study, field and initial product draf aranging; (2) testing with limited broad testing; (3) through experiment. analysis result shows that (a) validation step conducted by expert yield conclusion developed CER generally good term overall its instrument used (b) practicality it was o obtained the achievement aspec has fulfill criteria very practical; (c) test effect size on category significant improvement mostly high category. Broad two times student groups, Product experimental there score students’ mathematical reasoning group after implementation as (0.910) compare to control medium (0.664). btained