I struggle often with finishing a math lesson and being unsure of who really understood the skill and who is still struggling. I am now creating 'exit slips' for the end of math lessons. There is 1 problem on each slip as well as a 'self assessment' question at the bottom. The choices are:
This problem was really hard.
This problem was a little hard.
This problem was easy.
The standards are labeled at the top of each slip. I hope these are as helpful to you as they are me with assessing students quickly!