Now I do anyway. When that so-called modern math came in during the mid-sixties, there was much resistance to it. I lived in a progressive state back then, and I was a guinea pig for the modern math.
Sets, subsets, and intersections of sets is what I recall being drilled into us. I wasn't liking it too much at the time, it being new and all and me just riding a bus into the big county seat school, from a two-room first through sixth grade place closer to home.
The above math stuff may have degraded the teaching of classical mathematics. But those concepts have been proven to be handy for real-life sociology- the classification of the stupids becomes easy using those circles of section and intersection.