Included are two worksheets each containing 7 different problems and a key. Each problem asks the student to find both rate of change and initial value of a table, function, or graph. The two worksheet's answers correspond. Pair students in groups of two. Give them a partner 1 and partner 2 worksheet. After answering each question, they should make sure that they get the same answer even though they are given different problems. If they get the same answer, they should move on. If not, they should figure out which student made the error together and fix it. These worksheets are editable.