It is commonly known that the letter M in the two acronyms HPM and STEM stands for mathematics, and it is natural to regard mathematics as playing a significant role in science education. However, it seems that appropriate attention is not usually accorded to the role of M in the area of STEM where mathematics tends to be marginalized. In fact, throughout history one witnesses STEM at work so that the discussion of HPM and STEM in parallel will be beneficial to both. In both the historical and pedagogical aspects, it may be worthwhile to note that history of mathematics affords some means to mirror several different mathematical worlds in the context of HPM in a pluralistic way in order to offer a fuller view of the subject. In this paper I examine this issue through sampling many examples gleaned from the history of mathematics, particularly the role of M in the world of science and technology.