Math quiz on proportions for students. Featuring are two fraction values on both sides of an equation. One value is missing in the pair and students are required to find that value. Proportions reflect relationships expressed as fractions. Students are asked to find the missing part of that relationship to make in balanced. Skills in pre-algebra and making the subject of the formula come in handy here. 4th, 5th, 6th and 7th grades proportions revision exercise.