STOICHIOCARDS: A metacognitive problem-solving guide in stoichiometric calculations of solutions

This study aimed to develop and determine the effectiveness of STOICHIOCARDS, a metacognitive problem-solving guide, in enhancing Grade 12 STEM learners’ proficiency in concentration and stoichiometric calculations of solutions, and to evaluate its acceptability using the LRMDS evaluation tool. A quantitative pre-experimental one-group pretest–posttest design was employed with thirty-one Grade 12 STEM students from a National High School in Calumpit, Bulacan. The School Quality Assurance Team evaluated the material, while learners completed validated pretests, posttests, and a perception survey. Descriptive statistics measured performance and acceptability, and a paired samples t-test analyzed score differences. STOICHIOCARDS, developed through the ADDIE model and grounded in constructivist, cognitive load, and experiential learning theories, was rated very satisfactory across all domains. By integrating Concept, Guide, Reflect, and Challenge Cards with structured STAMP and SPICE strategies, the intervention offered scaffolded, problem-based learning that reduced cognitive load and strengthened metacognitive skills. Learners showed significant improvement (pretest M = 8.55; posttest M = 23.71; p < 0.0001). The study concludes that STOICHIOCARDS is an effective, acceptable instructional material that promotes independent learning, critical thinking, and confidence in chemistry.