This worksheet is separated into 2 columns. Each column has 15 questions covering topics from pre-Algebra and the first half of Algebra 1, such as evaluating functions, solving linear equations, graphing linear equations, working with fractions, working with percentages, and solving word problems.
Partner A completes the first column, and partner B completes the second column. What's special about this is that even though they had different questions, the topic addressed in each question is the same, and their final answers should come out the same. For example, Partner A question #3 asks to find the slope of the line that passes through (2, -5) and (8, -7). Partner B question #3 asks to find the slope of the line that passes through (1, -1) and (-2, 0). They should both get -1/3.
I do not tell the students this in advance. I ask them to each complete their own column independently. Then, I have them sit with their partner and compare answers. If they both got the same thing, it is likely correct. If they got different answers, they should work together on both columns and try to identify where the error was made. In my experience, they have usually been able to figure this out, and they do a great job of explaining to each other. There were only a couple times when I had to intervene and prompt a bit because both partners were totally stuck on what to do.
I have included an editable Word document in case you'd like to modify questions to better suit your level or content. There is also a PDF version. Both have answer keys.