Hasibuan, A.M., Pulungan, S.A. and Ramadhani, R. 2026. Theoretical Model of Intelligence Integration to Improve Self-Directed Learning in Mathematics in the 21st Century. Journal of Mathematics Instruction, Social Research and Opinion. 5, 1 (Mar. 2026), 1037–1048. DOI:https://doi.org/10.58421/misro.v5i1.1232.