My kid's math curriculum has been a disaster the last couple of years. Teachers started using lesson plans from Desmos (the tech company, which I haven't figured out how exactly they're pumping out curriculum material).

Back in my day, in basic math, you'd learn a couple of concepts a day and then did 20+ problems of homework, with variations of the main themes. But the new homework style is you do 1 or 2 problems for each new concept, and then you "expand your thinking" → trick questions, gotchas, problems that combine (non-obviously) today's lesson with one from last week, things you can't answer without peeking ahead to next lesson, and so on. This style is --I imagine-- good for kids who are already very good at math. I may have enjoyed it myself. But it's shit for most students, if you never spend hardly any time ensuring that the fundamental learning sinks in before moving on.