Cooperative-flipped classroom under online modality: Enhancing students' mathematics achievement and critical thinking attitude

•Critical thinking attitude influences mathematics achievement.•The short intervention does not affect the critical thinking attitude.•Flipped learning changed the learners’ perception for online modality.•Learners manifest Attitude towards self-directed learning.•CFc revealed better achievement than pure online class. The effectiveness of devoting more time to student-centered activities than lectures inside the classroom is discussed in the paper. The use of pre-recorded videos of lessons to supplement teachers' lectures gives students plenty of time to prepare and study the material in advance and allows teachers to spend the majority of their lecture time on interactive activities that will encourage students to think critically and improve their communication skills. The study aimed to enhance the mathematics achievement and critical thinking attitude of senior high school students. As shown by the quantitative data gathered, the study demonstrated how teachers' teaching methods and students' attitudes toward critical thinking affect students' ability to do mathematical tasks. Significant differences were manifested in the pre-test and post-test results of mathematics achievement of the CFc group as well as in the post-test result of CFc and the pure online groups. A significant regression model was also shown to support the influence of critical thinking attitude on the mathematics achievement of the participants. Meanwhile, the qualitative data gathered from the journal of the students revealed that, as one of the lingering effects of the CoViD-19 pandemic in the Philippines, more exposure of students to self-paced and technology-aided teaching materials contributes to their ability to learn independently and examine their self-regulative learning process, which is a result of inverting the classroom. Additionally, in a mathematics classroom, cooperative learning techniques proved to be an excellent complement to flipped learning.