This document has four exit slips on one page. Cut apart for a quick and unintimidating way to assess your kids on a lesson you just taught. I post a question or problem that matches my learning objective/target for the day and students answer in the space. Students self-assess by checking one of the boxes at the bottom.
(I've also used this as an "entry slip" to see what students remember from a previous day.)
Simply separate your slips into stacks of who "got it" and who didn't so you know who to reteach.