I'm reading a book about memory, and it seems to say that if you don't pay enough attention, don't repeat the input, or don't use the memory as output often enough, the information never registers or it fades.

Calculators have eliminated most of the cerebral input and output for math computation; it's reduced to finger input and optical reading of the calculator face. Meanwhile, the brain gets no practice. My student P-P (not Ping Pong or Poon Poon, but Pong Pang) may be slightly hobbled by his fingertips, but his brain is still working. I had another M1 genius, terminally shy, who wouldn't talk and was very slow, but he'd slowly process the math problem, check it out each step, and get the answer right. You have to work at it.

A brilliant store clerk might use their copious spare time to devise and play math games with the calculator instead of playing Ragnarok or FreeCell. But that would require critical thinking skills.

Found an old abacus at my GF's house this morning. Asked her if she knew how to use it. "No." It belonged to her grandfather and her father used it at his shop before calculators came out.

So, I set about showing her how to use it. A real mystery at first, but she quickly caught on and, I think, found it to be pretty neat. I'm hoping Dad will give us an expert's demo real soon now.