Here are a couple of options that you could use for exit slips. Each page will print 3 exit slips per page. There is one that could work better for older grades (with an extra line for the objective and a scale with numbers), and another one that could work best for younger grades (it's got a scale with smiley faces).
These work especially great for math interventions, but you could use them for when you are teaching or reteaching many of the common core standards. You could use it at the end of your intervention session to see if the students are understanding/ making progress. The students complete the exit ticket, you collect them, and then quickly sort into piles of "Got it," "Halfway there," or "Need more help."