Add/Sub Equations

Next week I will be introducing to my first graders addition and subtraction equations. I noticed that the common core standard for 1.OA.7 states that the students have to decide if it is a true or false equation. This seems like a hard concept to teach my first grade students. So I searched online for lessons on this concept and could only find one activity to do as a center. Below is an activity that I made that I plan on using with my students. I am in the process of making a smartboard activity to go along with the equations.
Click here for the equations activity.

Click here for the smartboard file (add/sub equations)