The aim of this study was to determine the relationship between students' metacognitive learning, critical thinking, scientific process skills, and academic achievements after the "Cell and Divisions" and "Force and Energy" units which have been processed according to different teaching methods. Furthermore, in this study, it is aimed to determine the variables that predict academic achievement. In the study, five different groups were selected from 7th grade students. In these groups, lessons were taught according to the Multiple Intelligence Approach, Problem-Based Learning, Peer Instruction, and Combined Method and the method recommended by the Ministry of National Education (2017). The sample of the study, in which the correlational survey method, one of the quantitative research approaches, was used, consists of 185 seventh grade students studying in two secondary schools in the Yakutiye district of Erzurum. As a data collection tool in research; Metacognitive Learning Strategies Scale, Critical Thinking Tendency Scale, Scientific Process Skills Test, and Academic Achievement Tests were used. As a result of the analyses made on the data of the students in different groups and the whole study group, significant relationships between variables were determined in terms of group specific and all data. In addition, in the hierarchical regression analysis, it was determined that scientific process skills were the most predictive skills for academic achievement for each group.