Troopers Brian Kross and Brian LaValley visited the students of Rachel Ruddle's math classes to teach them about crash scene investigations. Both of the troopers are currently in a special unit that takes measurements at critical crash scenes and does calculations to determine many factors of the crash.  Trooper Kross is a former West Middle School teacher before joining the Michigan State Police. He came back to answer the age-old question: "When are we ever going to use this"... The first day, he taught the students different formulas that used their knowledge of square roots and exponents. He taught them how to calculate speed, distance, and the coefficient of friction (drag). After his very informative lesson on crash investigations, he gave students an opportunity to do the calculations themselves and be very comfortable with the math. He came back the next day and brought Trooper LaValley to recreate a crash scene in the back of our school. They laid down skid marks and gave students scenarios to calculate how fast the car was traveling before the crash! They brought measuring tools and had the students engaged every minute of class.