This reads like so much of common sense and how we learned and practiced math through out our own school years decades ago.

A little baffled at why so much verbiage is dedicated to it.

Kids having notebooks dedicated for each subject for the academic year is news how?

All supplies and stationery stores include tons of notebooks in standardized dimensions. For math, we used grids in elementary school and then graduated to blank white pages from middle school. Teachers and schools would clearly mandate this -- and given how common and prevalent this practice was, it was almost tacit knowledge that no one needs to explain it or write about.