20 Fun Formative Assessment Examples to Try In Class (Plus a ... The first should be 10 to 15 words. The second is 30 to 50 words. The third is 75 to 100 words. By asking students to vary the lengths of their summaries, they'll have to remember different details as they refine their understandings. After, collect the summaries to see where knowledge gaps are. 4. Hand It In, Pass It Out