No surprise to me. I think I told the story about how, in the seventh grade, my school district introduced "modern math." It was supposed to help students learn higher mathematics such as algebra and trigonometry. Well, all it did for me was create confusion. I don't even think my teacher, Mr. White, understood it, let alone try to teach it to the class. I was hopelessly lost. When I did get to algebra, I could barely get a "C." Since proficiency in higher mathematics was a requirement back in the day, I ended up in a business college for 2 years (glorified secretarial school), which disappointed my father to no end. Did well as a secretary for 35 years, but I really wanted to be a lawyer.
Common core and other teaching methods today are even worse. At least, modern math didn't indoctrinate us on the glories of socialism, the perils of so-called climate change and all the other horse manure schools teach today. I can at least fill out a job application. Most of today's brainwashed youth can't.