This set of posters is based on the Common Core State Standard Initiative's outline of mathematical practices.
The describe varieties of expertise that mathematics educators at all levels should seek to develop in their students. These practices rest on important processes and proficiencies with longstanding importance in mathematics education.
Rather than practices, I have called them norms to encourage students to follow this set of beliefs at all times as they engage in problem solving. I have translated the complex wording into kid-friendly and simplified statements.