- Addition and subtraction using common core aligned mathematics. (Follows Common Core Standard CCSS.MATH.CONTENT.7.NS.A.1.D) Now these basic operations can be used to guide rockets into space and accelerate the space race. Try Intergalactic Addition and Subtraction! Assess proficiency in addition and subtraction according to education standards. Rewarding levels of gameplay maintain engagement. You will forget you were doing math as you launch rockets into space! You may optionally buy reports analyzing questions missed on addition and subtraction. Teachers and parents may find this optional feature particularly useful.