Another way of looking at it
In this situation, we should look for a way to invert
We know that we can divide any number by 1
without altering it. So ARR = ARR/1. So think of
ARR as a fraction.
Now think of the number of successful treatments
beyond baseline expectation as the unit on top of
the fraction (i.e. ARR) and the number of treated
patients as the unit on the bottom.