And yet, when I attended elementary school many decades ago we were taught by specialists beginning in the 5th grade. A system called "rotation" was instituted whereby we changed classrooms several times a day in order to be taught by specialists in mathematics and the sciences, in addition to other subjects. And this system of teaching continued throughout the 8th grade, after which we moved on to high school where specialized teaching had long been the norm. So it can be done. The interesting thing is that I never lost my basic numeracy skills and when working could easily solve problems that involved utilizing basic algebra. Some of the young staff coming in from university seemed amazed that in the "old days" acquiring such skills was commonplace even for those who didn't intend to enter a STEM field.