The Covid-19 pandemic has forced an immediate transition from face-to-face learning in classrooms to online learning, including math learning. Mathematics with abstract working objects is not easy to learn online. So, an excellent self-regulated learning ability is required. So far, many efforts have been made to improve self-regulated learning in mathematics learning. However, there are still gaps in improving students' self-regulated learning ability in online mathematics learning, especially in relation to the integration of GeoGebra into the Flipped Learning approach. The purpose of this study is to examine the effectiveness of integrating GeoGebra into the Flipped Learning approach to improve students' self-regulated learning ability in learning mathematics online during the Covid-19 pandemic. This research is a quasi-experimental study with a pretest-posttest control group design to compare the effectiveness of a GeoGebra-integrated Flipped Learning approach. A conventional Flipped Learning approach and a conventional learning approach increase students' self-regulated learning level in constructing their understanding of mathematical concepts during online learning in the Covid-19 pandemic. The study involved 60 students randomly selected from one of Indonesia's private universities. They were divided into three groups representing each approach. Pretest and posttest results were quantitatively analyzed using Normalized Gain (N-Gain) Score, Cohen's d effect size, and statistical descriptive. The analysis results revealed that GeoGebra-integrated Flipped Learning is more effective in increasing students' self-regulated learning level in online mathematics learning than the other two approaches. It is expected that the results of this study can provide insights into alternative solutions for improving the quality of online mathematics learning by increasing the level of self-regulated learning of students.

This research is categorized as Research and Development (R & D). As developed in this research is learning device that consists of lesson plan, student worksheet, and test. This research adopts ADDIE as a R & D model that stands for Analysis, Design, Development, Implementation, and Evaluation. The aim of this study are to describe the development process and to produce trigonometry learning device based on guided discovery method for students of grade XI Natural Science, as well as determine the effectiveness of trigonometry learning process using Guided Discovery method. To produce the trigonometry learning device based on guided discovery method for students of grade XI Natural Science, so it requires a validation from the experts and a trial to determine its practicability and effectiveness. According to the result of data analysis, it can be concluded: (1) trigonometry learning device based on guided discovery method for students of grade XI Natural Science fulfills criterion of valid, effective and practically, and (2) trigonometry learning process based on guided discovery method is effective.

There have been many efforts to improve elementary school students’ critical thinking skills in science through various learning methods. However, only a few research results show efforts to improve critical thinking skills through HOTS-based science questions for elementary school students. Therefore, the purpose of this study is to test the effectiveness of student habituation with HOTS-based science questions in improving elementary school students’ critical thinking skills in science. Quasi-experimental methods were employed in this research with a nonequivalent control group design involving a treatment class and a control class. The treatment class gets treatment in HOTS-based science questions habituation during the learning process, while the control class in conventional approaches. A total of 60 students is from one of the elementary schools in Surakarta, Indonesia. To take data related to students’ critical thinking skills, they were given pretest and posttest where each test used HOTS-based science questions in an essay. The obtained data from the tests were then analyzed using descriptive and inferential statistical techniques. This study showed that the average of critical thinking skills in science of students in the experimental class was higher than the control class, with a positive mean difference of 0.4226. Based on these results, it is recommended that the results of this study can provide an overview to educational practitioners at the elementary school level and researchers in the field of science education related to efforts to improve elementary school students’ critical thinking skills in science through the habituation of HOTS-based science questions.

This study aims to develop a learning model based on the theory of realistic mathematics education and child-friendly learning for teaching mathematics in junior high school. This research is conducted using Plomp’s educational design research that consists of four development phases: 1) preliminary investigation, 2) designing, 3) realization, and 4) revision, evaluation. In addition, this study also tests the mathematics instructional model prototype being developed and validated by an expert. Based on the analysis, it can be concluded that: 1) the teacher’s learning management in the implementation of realistic and child-friendly learning model can be classified “very good”, 2) the prototype model is categorized “very good” in improving students’ activities , and 3) the students’ responses toward the developed mathematics instructional model are "positive”. Moreover, the syntaxes of realistic and child-friendly learning model for teaching mathematics in junior high school have been formulated, namely: 1) explaining learning objectives and motivating students, 2) providing contextual problems students familiar with, or horizontal mathematization, 3) processing abstraction or vertical mathematization, 4) devising strategies, 5) communicating solution in a discussion, and 6) giving inferences of mathematics subject-matter.