Kristina Porter had her students explore different kinds of screws — their form and function — with a loupe and The Private Eye Questions. Her students learned that screws are actually simple machines! The students began by closely observing a screw with a loupe and created a group list answering the first Private Eye Question: “What else does it remind you of?” They learned one of the uses a screw: to hold objects or materials together. They each did a close-up loupe drawing of a screw, and tried out screwing pieces of wood together. Then the students would not be denied: they wanted to find the top of every screw holding something together in the classroom — and then in the school at large! They were definitely not just screwing around.

A little background on screws:

“The screw was one of the last of the simple machines to be invented.[6] It first appeared in ancient Greece,

A screw is a mechanism that converts rotational motion to linear motion, and a torque (rotational force) to a linear force.[1] It is one of the six classical simple machines.

Geometrically, a screw can be viewed as a narrow inclined plane
wrapped around a cylinder.”
      Source: Wikipedia