The main purpose of this study was to develop the Mathematical Metacognition Scale (MMS) on 5th – 8th graders in elementary and junior high schools. The present study included two phases: pretest and test. By adopting purposeful sampling and cluster sampling in both phases, 457 and 861 students were selected for the pretest and the test, respectively. 

Exploratory factor analysis and confirmatory factor analysis were conducted with the pretest data. The confirmatory factor analysis resulted in three factors including metacognitive knowledge, planning and monitoring, and evaluation. The Cronbach´s alphas of the MMS subscales were .87, .87, .72, and .90 for the total score, which indicated good reliability.

Measurement invariance was conducted to the test and indicated gender invariance. Therefore, it showed that the MMS has good construct validity.