As an educator, I think about this a lot. One approach I'm prototyping for a (hopefully freely available) course on reinforcement learning is to translate dense math expressions into English sentences, and then link each piece of text<=>math with a corresponding color. (Quick example I just uploaded: https://gfycat.com/favorablemintyharrier ).

By doing this consistently, I can highlight the link between math symbol and corresponding concept, and help the student learn how to read and interpret dense constructions as we go.

(Note that this approach is intended to be used as part of a larger explanatory strategy, so please assume the example is embedded in an appropriate context.)