CCSS.NCEX.Math.Content.7.EE.B - Solve real-life and mathematical addition and subtraction problems using numerical and algebraic equations.
CCSS.NCEX.Math.Content.7.EE.B.4
Mathematics
Understand the concept of equality with models (i.e., if there is a quantity of 5 on one side of the equation and a quantity of 2 on the other what quantity is added to make it equal).