If you are unable to recite 7x6 and reach for the calculator for it, I don't think many people will memorize it. I did the same, up to 20. I've used it so much

If you are unable to recite 7x6 and reach for the calculator for it, I don't think many people will memorize it. I did the same, up to 20. I've used it so much since then that even though it seemed silly at the time of learning, it has proved that my total time saved is far greater than the time spend memorizing it. It helps that I went to STEM for university and in general are interested in it. But I'd say over a lifetime average Joe/Jane that handle a normal persons finances will at some point have saved more time than spend learning it.