"An important requirement in the Common Core is the need for students to discuss ideas and justify their thinking. There is a good reason for this: Justification and reasoning are two of the acts that lie at the heart of mathematics. They are, in many ways, the essence of what mathematics is. Scientists work to prove or disprove new theories by finding many cases that work or counter-examples that do not. Mathematicians, by contrast prove the validity of their propositions through justification and reasoning."

""The mere use of the term in the ad does not mean that he hiring committee is looking for someone who is genuinely transgressing or crossing disciplinary boundaries," crossing methods and topics as they teach, publish and coordinate with others, they wrote. "They may just be looking for someone to co-teach core curriculum classes with someone from another department.""