The focus of this action research was to adapt Bruner’s 3-tier theory to enhance conceptual knowledge of teacher trainees on integer operations. It looks into how learners' conceptual knowledge of integer operations changes over time, as well as their attitudes toward using the 3-tier model. Eighty-two (82) teacher trainees, who were in their first year semester one of the 2020/2021 academic year were purposely selected for the study. Data was collected using test and semi-structured interviews. The study found that using Bruner’s 3-tier theory contributed to substantial gains in conceptual knowledge on integers operations among learners.  It was also found that learners proffered positive compliments about the Concrete-Iconic-Symbolic (C-I-S) construct of lesson presentation and how it built their understanding to apply knowledge on integers operations. Learners also largely proffered positive image about C-I-S construct as it aroused interest and activated unmotivated learners. On these bases, the study concludes that lessons presentations should mirror C-I-S construct in order to alleviate learning difficulties encountered on integer operations. To do this, the study suggests that workshops on lesson presentation using C-I-S construct be organized for both subject tutors, mentors and lead mentors to re-equip their knowledge and to buy-in the idea among others.