I am wondering the same thing about my kindergarten class. One way that I found that would be a cool way to implement STEM in the class is encorporating engineering into literacy. This would be too hard of a concept for my kindergarteners, but I feel like in 2nd grade, you could present and read a book with some sort of problem. Pose a challenge to your students to design a solution to the problem in the book! We talked about this in our STEM class the other day, and I thought this was a really great idea!