One of the things we did in class was attempting to start a fire the old-fashioned way, with only the following materials: flint (a rock), steel, charcloth (charcoal cloth) and our own hands. We struggled a lot and only managed a small spark, but we weren't the only ones. Very few people in our school were able to start a fire, which just goes to show how the times have changed, considering that back in the early 1900's, everyone could start a fire using this method.
Another thing we did in class was make hardtack, a stiff, dry, cracker-like substance that soldiers ate in WW1, because it was easy to make, needed only three ingredients, and could last a lifetime. The three ingredients are: flour, water, and salt. In order to make, you simply mix them together, flatten it out, poke holes, bake it and let it dry. Two people in our group made hardtack, (only one pictured), and both batches came out very differently, because despite the lack of complexity in ingredients, there are many factors in determining how the hardtack will look, feel, taste, and even smell! Some factors include: the amount of each ingredient used, the thickness of the flattened piece of dough, the amount of holes poked, how long you cook it for, what temperature you bake it at, the type of oven you have and much more!