From YouTube, produced by Lawrence Perez
Video starts with the definition of proportion, which is an equation of two rations, or a fraction equal to a fraction. On a proportion problem you can cross-multiply to solve proportion problems. They show what a non-proportion problem looks like and how to solve it (review). Then they show a few examples of solving proportions, using LCD on the fractions. Other examples and numbers are shown. Video is good quality and good for all students as a review or initial learning of the topic.