The Impact of Flipped Teaching on Students’ Critical Thinking, Collaboration, and Mathematics Retention in Southwest Cameroon

Lecture-based mathematics instruction often struggles to build higher-order thinking or lasting knowledge in secondary schools. To tackle this, the present study employed an explanatory sequential mixed-methods design to test the flipped classroom approach with 120 Form Two students in Buea, Cameroon. The design consisted of a 2x2x2 factorial quasi-experiment, crossing instructional method, gender, and socioeconomic status, followed by a qualitative phase. Grounded in Vygotsky’s social constructivism, the flipped group (n = 65) experienced ten weeks of pre-class videos and digital handouts, while the control group (n = 55) stayed with traditional lectures. Critical thinking was measured using an adapted California Critical Thinking Skills Test, collaboration through self-reports and teacher ratings, and retention with a delayed test twenty weeks after the intervention. The ANCOVA results, adjusted for pretest scores, showed clear benefits for the flipped group. Critical thinking rose sharply (F = 41.500, p < .001,  η²_p = .262). Collaboration improved modestly (F = 4.081, p = .046, η²_p = .034). Retention showed the strongest effect (F = 174.877, p < .001, η²_p = .493). Gender did not moderate outcomes, but socioeconomic status did. Numbers alone don’t capture the full picture. To explain the findings, we interviewed fifteen students from the flipped group, representing varied achievement levels, genders, and economic backgrounds. In semi-structured conversations, they described how pre-class videos shaped problem-solving, how peer discussions unfolded, and how replaying lessons weeks later helped recall content. Reflexive thematic analysis revealed the cognitive, social, and structural mechanisms behind the statistical results.