I have to take issue with some of things to which children's lack of attention span and long-term memory are attributed. In my experience, this egan log before the infamout 'technology' was avaiable. We had the Radio and TV and landline phones, and they were under the control of parents, who dediced what could be listened toor watched and how long for. On warm summer evenings, TV was not an option, you played outside in the fresh air!
But fashionable teaching methods in Primary Schools started the rot. No proper division into subject and lessons. No "Maths before break, English after break, History, Geography, Science, Art and Music in the afternons". Kids sitting groups chattering among themselves, rather than sitting in rows paying attention to the teacher or working on their own. Kids being asked their opinions instead of being given information and taught techniques. No more "ears and eyes open, mouths shut". No more learning multiplication tables and poems by heart. No more mental arithemtic.
Attention span has to be increased by enforced concentration. Memory has to be trained by memorising things. Motivation can be vastly improved by the judicious application of the occasional thick ear. You can reward and incite bad behaviour by exclusion, counselling (ie getting out of class) or by 'positive reinforcement' (bribery), or you can put and end to it with public humiliation (girls) or six of the best (boys).
The process of education is one of turning a rabble of evil little horrors into a group of responsible young people. A process that requires Machiavellian subtlety, the strategic grasp of a Sun-Tzu or a Musashi, and a certain amount of brute force.