<p>Engineering is mostly what you have already been doing in calculus. Find a problem, learn the steps to solve it, repeat. Mostly computation to critical thinking. </p>
<p>Math major is the other way around, it’s mostly critical thinking compared to computation. Do you like mathematical proofs, the logic behind what you are doing, and are you good at seeing hidden patterns? Youtube has plenty of videos on abstract algebra and real analysts, check them out and see what you think. </p>