This activity has students practice simplifying ratios, writing ratios that require unit conversions, and finding missing values in proportions.
Students divide into groups of 4 and each student is assigned a problem. They find the sum of the solutions to their problems and present it to the teacher. If the solution is correct, they move on to the next set of problems. There are 5 sets total, and they increase in difficulty as the students progress.
Since this activity was primarily used in a low level algebra and/or geometry class, the problem in the last set that has x-squared only uses the positive value to find the sum.