From what I&#x27;ve seen of the common core, 90% is fine and just plain old math stripped of any historical baggage.  The 10% that is bad is the ideology that math is more ambiguous or less certain than it has been portrayed in the past.  This is partly based on politics, and partly on the misuse of mathematical philosophy.<p>I remember being given problems that were plain wrong, e.g. Q: How many miles would a person walking 3miles&#x2F;h walk in 2 hours? A: 6 miles.  I always asserted that the answer is 6, not 6 miles, since the unit is given in the question.  Small errors like this in teaching add up to math that looks like a collection of arbitrary commandments that must be memorized.  It&#x27;s understandable people want to move away from this.  But this solution is to fix all aspects of teaching so that everything is completely correct, not to pretend that math allows multiple correct answers.<p>We should be teaching that you can express a well formed question in words, to which there should be a unique correct answer.  Word problems shouldn&#x27;t be an added layer of obfuscation, but rather a map from the semantics of math to the semantics of the real world, to test that the student understands this mapping.  It&#x27;s a bit like talking to a backend programmer and saying &quot;if a user did X, then they did Y, what would your function return, and is that correct&quot;?  It forces the programmer to consider not the internal logic of their own code, but how that ultimately maps to what the user sees.