1. Make sense of problems and persevere in solving them. 2. Look for and make use of structure. 3. Look for and express regularity in repeated reasoning. 4. Give examples of linear equations in one variable with one solution, infinitely many solutions, or no solutions. Show which of these possibilities is the case by successively transforming the given equation into simpler forms, until an equivalent equation of the form x = a, a = a, or a = b results (where a and b are different numbers).