This is pretty relevant, as nowadays Lehrer’s joke apparently needs explaining. In “New Math,” he sings as quickly as possible to explain a math problem in a deliberately obfuscatory way, in order to make fun of New Math. But if you watch a video of the problem, all he’s doing (for base 10, anyway) is the borrowing method, the one that GenXers all grew up with. The “reveal” is because they sympathize with the singer about how confusing newfangled things are without listening closely enough to realize how traditional they are.
New Math didn’t improve understanding and it decimated basic arithmetic skills. And “trying to improve” is not necessarily the same as actually improving. To avoid further discussion of this subject in this thread, here’s the discussion from 4 years ago. Explain this ‘new math’
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I’ve participated in umpty-ump threads over the years correcting misconceptions about Common Core. I read that whole thread you linked to. You had one post in it making the same uncited claim you make above. Somehow I missed that thread when it happened; but in my many years in the classroom, I’ve yet to see any evidence to support your assertion about a negative cause-and-effect relationship between New Math (or Common Core) and basic arithmetic skills. If you’d like to start a new thread where you defend that assertion, I’m so there 
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