[StanislavPetrov]

I learned math in the "traditional" method through several levels of calculus in college (decades ago) and found a young relative's common core math curriculum to be extremely cumbersome and far more confusing for the student. In my opinion its far better to teach a student to understand a mathematical principle than to force them to absorb your prescribed method of understanding. You could know a mathematical principle backwards and forwards and be an expert in the field and still end up baffled at the nonsensical "core curriculum" methods and jargon.