Students work in 6x groups, each group solving a different stoichiometry problem on their personal paper. Once verified correct, they put their problem on a white board. They then take a gallery walk among the other white boards containing stoichiometry problems and pick 2 to include on their papers.
I include 6 different stoichiometry problem sheets with one problem to solve and blank grids for 2 other problems per sheet in pdf format.
I use this in my stoichiometry unit as a break from the usual practice problems. I usually copy some kind of bell work or warm-up on the back of these sheets, and then have the students flip the sheet and move to the whiteboard designated by the group number to incorporate a little movement into the day. Another benefit is that students who are struggling will have access to peer support to help figure out how to get the correct answer.
I usually give about 20-30 min. for this activity.
Students should be able to balance reactions and be able to attack stoichiometry problems on their own before doing this activity. Students will probably need a calculator for this activity, as well.
I have found this NOT to be an effective way to introduce stoichiometry.
If you would like this sheet to be customized to your content, I am willing to do so, Follow instructions in the document to let me know what you want.
Check out my info page: https://sites.google.com/site/aa31labs/