From YouTube, produced by Lawrence Perez
In this video they show to use a percent structure to solve many percentage problems. The structure is "A percent of a total is a portion." Then they break it down into an equation, percentage times total is equal to the portion. They go through a number of examples. The formula is good and can be used at any level, but the word problems are definitely pre-algebra. Video is good quality and good for all students as a review or initial learning of the topic.