Lol, I take that back..... I just had to derive something like this.
Log(10)(1 - KE/PEi) / Log(10)(1-.12) = Number of Bounces Required for a bouncy ball to lose enough energy when it dissipates 12% of its KE every bounce, to reach a specific Height AKA KE in this equation.
I had to look up logarithms and beat myself in the face with a stick while doing it, I think the people who came up with logarithms, also came up with uo's mathematics. Its all Degenerative.... lol