Feed the Bears
Line up three and the bear eats. Berries are worth one. Salmon is worth six.

Soak it, pull it apart, and find out what the owl ate.
The full bench procedure, start to written-up finish. The closest thing here to a real lab, and the one to book a double period for.
Printable activities that go with it:
Line up three and the bear eats. Berries are worth one. Salmon is worth six.
Hunt all night, carry it home, and decide which owlet eats.
Five tangled lines. One of them ends at tonight's dinner.