I like questions where students are asked to compare two options.  For example;

I like to see how students answer these questions. The reason i have 30 is because i gave each question out to a students and they answered it in their book. I was interested in how they approached it and if they had more than one approach, I was also interested if the person next to them could find a simpler way. Here is the worksheet with all 30 questions. Feel free to use them how you wish. I give each student one each or stick one in each book when i take their books in. I then mark their responses.

30 Compare Questions