1. Reason abstractly and quantitatively. 2. Construct viable arguments and critique the reasoning of others. 3. Use properties to produce equivalent expressions. 4. Understand solving an equation or inequality as a process of answering a question: which values from a specified set, if any, make the equation or inequality true? Use substitution to determine whether a given number in a specified set makes an equation or inequality true. 5. Use variables to represent numbers and write expressions when solving a real-world or mathematical problem; understand that a variable can represent an unknown number, or, depending on the purpose at hand, any number in a specified set. 6. Look for and make use of structure.