Levers are one of the basic tools that were probably used in prehistoric times. Levers were first described about 260 BC by the ancient Greek mathematician Archimedes (287-212 BC).
A lever is a simple machine that makes work easier for use; it involves moving a load around a pivot using a force. Many of our basic tools use levers, including scissors (2 class 1 levers), pliers (2 class 1 levers), hammer claws (a single class 2 lever), nut crackers (2 class 2 levers), and tongs (2 class 3 levers).
 A Type 1 Lever. |  A Type 2 Lever. |  A Type 3 Lever. |
| A Type 1 Lever. |
In a Type 1 Lever, the pivot (fulcrum) is between the effort and the load. In an off-center type one lever (like a pliers), the load is larger than the effort, but is moved through a smaller distance.
Examples of common tools (and other items) that use a type 1 lever include:
| Item | Number of Class 1 Levers Used | |
| see-saw |  | a single class 1 lever |
| hammer's claws |  | a single class 1 lever |
| scissors |  | 2 class 1 levers |
| pliers |  | 2 class 1 levers |
| A Type 2 Lever. |
In a Type 2 Lever, the load is between the pivot (fulcrum) and the effort.
Examples of common tools that use a type 2 lever include:
| Item | Number of Class 2 Levers Used | |
| stapler |  | a single class 2 lever |
| bottle opener | | a single class 2 lever |
| wheelbarrow |  | a single class 2 lever |
| nail clippers | | Two class 2 levers |
| nut cracker | | Two class 2 levers |
| A Type 3 Lever. |
In a Type 3 Lever, the effort is between the pivot (fulcrum) and the load.
Examples of common tools that use a type 3 lever include:
| Item | Number of Class 3 Levers Used | |
| fishing rod |  | a single class 3 lever |
| tweezers | | Two class 3 levers |
| tongs |  | Two class 3 levers |
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