To calculate markup percentages, multiply the starting value by the markup percent and add that number to the original value. Understand markup percentages with advice from a standardized test prep instructor in this free video on mathematics. Expert: Brian Leaf Contact: www.brianleaf.com Bio: Brian Leaf, MA, is the author of McGraw-Hill's Top 50 Skills for SAT/ACT Success series and has instructed SAT, ACT, GED and SSAT preparation to thousands of students. Filmmaker: David Pakman