Metacognitive process in Algebraic Solving Problem Based on The SOLO-Plus Taxonomy is an activity series done by students related to their knowledge about process and result of their own thinking in planning, monitoring, and evaluate their process and result of their thinking when solving algebraic problem based on 7 level: prestuctural, unistructural, multistructural, semi relational, relational, abstract, and extended abstract.

The purpose of this study is to describe middle school students’ metacognitive process in Algebraic Solving Problem Based on The SOLO-Plus Taxonomy. We used qualitative approach and conduct algebraic problem test and interview to gain the data. The subjects in this study are 2 eight grade students from SMP Negeri 2 Randuagung-Lumajang. We chose the subjects with similar performance grade by mathematic performance test. We analysed using data reduction, data display and drawing conclusions. To gain valid data we used time triangulation.

The result shows that metacognitive process for the subjects namely AR and AG in Algebraic Solving Problem Based on The SOLO-Plus Taxonomy, they both did planning, monitoring and evaluate the process and the result of their thinking in every step they take in solving problem (understand, plan, do, and check).

When we interviewed the subjects, there are differences between them in checking time and other strategies when understanding problem, planning solution, doing solution and checking. Subject AR didn’t think about time and other strategies in solving problem.