One of my favorite activities involves everyone ending at different times. Instead of having students do busy work, one option I use is “silent STEM.” I have supplies in baggies and students are given an end result instead of directions.
This edition of “Silent STEM” involved baggies of Little Bits. We had the bits to make a flashlight. The students had the option of using a supply table if they needed more parts (to make the outside of the flashlight).
I loved that everyone’s results were slightly different, and it gave students another chance to be hands on without distracting from the first activity of the period.