Lesson: Archaeological Grid Lines 2

 

Objectives:

!    1.07 Estimate the square root of a number between two consecutive integers;     using a calculator, find the square root of a number to the nearest tenth.

!    2.06 Use the Pythagorean Theorem to solve problems.

!    2.12 Select appropriate units and tools for measurement tasks within problem-solving situations; determine precision and check for reasonableness of results.

 

Materials:

·        Pythagorean theorem Worksheet

·        Kite String

·        4 sticks per group

·        1 meter stick or yard stick per group

·        1 Carpenters Square for the teacher

·        Paper

·        Pencil

 

Setting the Stage:

Have the students imagine they are a team of archaeologists who have found an archaeological site.  Students will learn how to prepare gridlines for the site.

 

Procedure:

·        Provide students with background information on grid lines if they have not previously read it.

·        As a class have students decide how they would get a right angle in their grid lines on the ground. Discuss Pythagorean Theorem, review the Pythagorean Theorem as a means to create grid lines with right angles.

·        Students must complete worksheet using Pythagorean Theorem.

·        Students will get into pairs and be given 4 sticks, kite string, and meter stick.  Students will then go outside and must create a gridline of 2x2 feet.

 

Evaluation:

Pythagorean Theorem worksheet will be graded.

Teacher will use a Carpenters Square to test the right angle of the group

 

Closure:

Students sit in a circle an discuss the following:

• What problems, if any, occurred?
• What would make this work easier?
• How would we create a 10x10 foot grid?

 

 

Extension:

Students may create an entire grid of 1x1 squares to practice putting squares together

 

Background Information: Grid Lines

 

Once a site has been dug (or in the case of sites with no depth, the surface artifacts have been collected), it is gone forever and can never be replaced with another just like it. Because sites are destroyed during collection or excavation processes, archaeologists record them in detail to preserve the context of all the artifacts and structures. Archaeologists in the future can study an excavated site only if good notes and maps are made.

 

One way archaeologists preserve context on paper is through the use of the rectangular grid, or Cartesian coordinate system. The first step in the excavation process is to establish a grid. A site datum is set at an arbitrarily chosen location and is designated as (0,0). Two perpendicular axes or lines intersecting at the site datum are then established and a rectangular grid is superimposed over the entire site. Each square on the ground is marked with numbered stakes in the corners, so that each square or grid unit has a unique "name" referred to by its coordinates. The coordinates indicate the distance of a given point

north, south, east, or west from the site datum.

 

Once the grid is established, all artifacts and structures are measured and recorded using the system. Before excavation actually begins, all artifacts visible on the surface are collected and their locations on the grid are recorded. As the excavation proceeds, materials found under the surface are similarly recorded and collected. When the archaeologist returns to the laboratory, the maps and the data recorded in the field can be used to make inferences about past events and the lifeways of the site's inhabitants. If the exact location of each artifact transported back to the laboratory is known, then the object can be tied to its

context within the site.