Your kids know "associative property" use?----Say what?!!!-----------Kid misses Common Core math problems because he didn’t use ‘friendly’ numbers

Kid misses Common Core math problems because he didn’t use ‘friendly’ numbers [pic] | Twitchy:
"In Common Core math, it often is not good enough to get the correct answer.
Instead, students are required to show “higher order” thinking skills — in this case, use of the associative property. 
Yes, the associative property is important and should be taught at some point.
Unfortunately, we suspect that many 7-year olds will not be able to understand this particular assignment. With limited days in the school year, wouldn’t second graders — second graders! — be better off spending their time attempting to master the traditional subtraction algorithm?"