So if the method had a power of 3, it’d be 0.9 * 0.9 * 0.9 = 0.729, instead of 0.9. Those five standard Classes use a power of 1 – 5. And yes, Quintic and Strong are the same. These functions are usually written with 4 arguments : @t is the current time (or position) of the tween. Math - easing functions for bell curves?