6.EE.2a:
Expressions And Equations
Apply And Extend Previous Understandings Of Arithmetic To Algebraic Expressions.
Write expressions that record operations with numbers and with letters standing for numbers. For example, express the calculation "Subtract y from 5" as 5 - y.
6.EE.6:
Expressions And Equations
Reason About And Solve One-Variable Equations And Inequalities.
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.
