Not saying that teacher didn’t suck, but method can be important in earlier math classes. So much of early math is about developing number sense and just understanding what is being represented by a mathematical statement. If a method is a stand in for a larger level comprehension, say, showing that 3*2 is also represented by three rows of two, ie

🟦🟦
🟦🟦
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Just regurgitating a memorized number doesn’t show that deeper understanding.