<p>In many countries across the globe, a low-prestige image of Technical and Vocational Education and Training (TVET) persists. Students enrolled in TVET programs may sometimes be subjected to lower teacher expectations. Expectation impacts the level of instruction these students receive. And yet, being equipped with problem-solving, mathematical reasoning, and higher-order thinking skills is important and expected from students and workers in the technical and vocational fields. As a result, students receiving TVET need both conceptual and contextual aspects of the Mathematics curricula. The mathematical learning process should involve understanding the process in which Mathematics rules are used (instrumental understanding) as well as the reasons behind rules and networking of concepts (relational understanding). This study performed a quantitative analysis of diagnostic testing of TVET students from a Caribbean island, to determine the favorability of relational understanding in critical areas of Mathematics. The results guide education stakeholders to the Measurement area, where emphasis is required on the relational understanding of concepts such as area and volume of shapes. This study highlights the need for careful selection of textbooks to increase opportunities to promote relational understanding.</p>