It's tricky to find solid footing for a sense of certainty, as
   the ever changing world of academic/science (along with the
   representations/misrepresentations of such in media) makes it
   difficult to sort it all out.

   The current trend in educational psychology is something they
   call Grit. Much of the Common Core curriculum changes in the USA
   are inspired by a pop psychology book a few years ago mentioning
   Grit as the best indicator for success.

   It became VERY popular among educators. It help me somewhat
   because figuring this out allowed me to explain to my nephew
   when he was in the 4th grade (9 years old) last year, WHY it
   seemed they were making math harder.

   It's because they are.

   I showed him how he could do in his head ANYWAY, and ALSO do he
   "show your work" routine for the teacher to be able to show to
   the principal who can show it to the board who can show it to
   the State so that the school can get money to pay for the
   teachers.

   He understood it right away and his grades went right back up.
   It's a shame the game is that way, but it is. I digressed -
   sorry about that smile emoticon