I think that&#x27;s what you get with unsupervised learning.<p>Tricks only get you so far, you can&#x27;t do 6+7 on fingers or 7·7 as (4+3)(4+3) <i>(I had a huge problem with this one, too many numbers to track)</i>. So you fail. And when you fail, you memorize the problematic cases and go on with tricks based on those.<p>And yes, it&#x27;s completely incomprehensible for people who learned the pencil-and-paper algorithms and think that those are the end of the world.