This study aims to examine the improvement of metacognitive abilities in learning mathematics through a variety of formative assessments. The study applied an experimental approach with a pre- and post-tests control group design. Six classes of students were chosen by cluster random sampling as the sample, with two classes serve as the experimental group with performance assessments, two classes serve as the comparison group with essay assessments and two additional classes serve as the control group with multiple choice assessments. The instrument to measure metacognitive ability was developed specifically for the pre-and post-tests. The gain score was analyzed using a one-way ANOVA and continued with the Scheffe test. The study discovered that students who participated in learning with formative assessments of performance showed the highest levels of metacognitive skills followed by those who participated in learning with formative assessments of essays and those who participated in learning with formative assessments of multiple-choice questions came in third. These findings lead to the conclusion that formative assessment of performance has a positive effect on improving metacognitive abilities. According to the characteristics of learning mathematics, this situation might happen because the performance evaluation includes activities that are difficult, comprehensive and associated with daily life. In addition, performance assessment also has intrinsic value because it requires students to organize and present material in their own way. It is recommended that mathematics teachers use formative performance assessments in order to enhance cognitive capacities.