The how is what is supposed to be being taught to children at the moment and why the math classes are shifting away from times tables and such. Rote memorization doesn't produce as good of a result as understanding how the calculations work on more intuitive level. I can't find it at the moment since I'm in the metro with poor connection but there was an article about how geometry was taught in such a way to teach kids to distrust their own common sense and instinct by relying on Byzantine rules from the getgo instead of letting kids naturally explore geometry and get a feel for shapes, angles, etc. (with the rules coming later)
The move away from rote can have an unexpected draw back. Fast mental estimation requires rote learning , otherwise you draw a blank. over-reliance on tooling like calculators have made mental skills like that decrease over the years.
