Add Them Up - Equations of Line

I wanted to do something a little different with my grade 9 class as they prepare for EQAO and their final exam. My plan was to focus on equations of lines so I made some "Add Them Up" questions. I formed random groups of four students by having them draw playing cards and each group received the same sheet. On it were four different versions of the same question. Each group member worked on one question (they took small whiteboards for this) and when they all finished, the sum of their answers was written in the centre. This makes checking answers easy for me and forces the group to find mistakes if the sum is incorrect. Here is the first one:

I made five of these, with the level of difficulty increasing each time. Here is the last one:

I photocopied these on five different colours of paper so that I could easily tell which one each group was working on. I was surprised by the number of mistakes, though many came up when they had to add fractions to get the sum of their answers. Fractions are hard. I purposely made many of the answers fractions so that they would be forced to practice these skills. As it turns out, some were really "ugly" so I have edited them and they are now more reasonable.

I was really impressed with my class - they helped each other and taught each other and worked as teams in the best way. I answered very few questions, although I didn't stop walking around and checking in with the groups the entire class.

Here are all five.