Common Core Alignment:.

6.EE.2:

Expressions And Equations

Apply And Extend Previous Understandings Of Arithmetic To Algebraic Expressions.

Write, read, and evaluate expressions in which letters stand for numbers.

6.EE.5:

Expressions And Equations

Reason About And Solve One-Variable Equations And Inequalities.

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.