A batting average is number of hits divided by the number of at bats. Slugging Percentage is a mathematical equation. A HR is fout points, triple 3 points, a double is two, and a single is one. take the number of points added up, then divide by the number of at bats. For example, a batter goes 1 for 4 and hits a home run, which is four points. Four points divided into 4 at bats equals 1.000 slugging percentage.