As someone who had a hard time focusing in school, modern books with lots of text actually made it harder to focus than books with less text and more information per word. I can read 20 words and then think about those, I can't read the same information if it is spread out and hidden within a 2000 words text.

So maybe kids has problems focusing partially due to modern pedagogy? Every word you write down has a cost to the reader, and the less attention span the reader has the more that cost matters. Drown them in too many words and they will just zone out since their attention span didn't last long enough for them to reach the important parts of the text.

Drill exercises require very little attention time but are the keybto learning a topic and understanding it. This is nothing new but it is usually despised because “boring”…

Like food and architecture, math pedagogy has been affected by the progressive diseases of modern civilization, so new often does not mean good.