An object of mass m slides down an incline with angle. Which equation allows you to correctly calculate the normal force on the object?

Normal force is described as the force exerted on an object by gravity. Therefor, the normal force is mg, mass times gravitational force. However, as a product of the failure of our education system, this is taught differently in different schools. If normal force is described, where you're being taught, as the downward force, then it is mgsin (x), where x is the angle of inclination, so it's mass times gravitational force time the sin of the angle.