When I need to keep track, I have a wooden block drilled with 24 holes. I
make the students return the pencils to this spot at the end of the hour,
monitoring, if necessary the return. I can tell at a glance if, for
instance, three are still missing, and I will tell the class they they are
not going anywhere until all the pencils are returned. Once students are
trained in this manner, I can loosen up because the materials will be
returned as expected with a minimum of supervision. Erasers can be
returned to a cardboard taped to a counter with a silhouette for each
eraser (trace around 24 erasers so each has a specific spot). The students
begin to understand that I want them to use good materials, but I want them
to care for them. Given a place to return things, they comply. Our large
sets of Prismacolors are named after famous artists - Leonardo,
Michelangelo, Rembrandt. If only a few sets are shared, I can ask for the
set by name..."Where is Rembrandt?"