Coin Archeology

Summary

In this multiple day lesson, students will search for coins with a metal detector, and will plot their discovery location on a grid. Students will use coordinates to represent locations of coins found.

• Cent
• Nickel
• Dime
• Quarter
• Half dollar
• Dollar

• Generic

Objectives

• Students will be able to create a grid on graph paper representing the search area and use coordinates to represent locations of coins found with a metal detector.
• Students will be able to record the locations, depths, and other information about coins found with a metal detector on their grids and in a group "catalogue of finds."
• (Older) Students will be able to compare the dates of all of the coins found to determine if a correlation exists between their relative depth in the soil and the length of time they have been buried.

• Science

• Math

Class Time

Sessions: Three
Session Length: 45 minutes
Total Length: 91-120 minutes

Groupings

• Whole group
• Individual work

Terms and Concepts

• Coins
• Logical reasoning
• Patterns
• Problem solving

Materials

• 20th-century coins of various denominations (the number buried will vary depending upon group size and search area)
• 2 metal detectors
• Small spades (one per team)
• Clipboard, graph paper, pencils (one set per team)
• 75 to 100 flag markers (either commercial or sections of hangers with flagging material tied to each)
• Metric rulers (one per team)
• Overhead projector with transparency of matching graph paper grid
• Sharpie markers (8-color set)

Preparations

• Bury U.S. coins of all denominations with dates spanning the 20th century. If possible, include Mercury and Roosevelt silver dimes, Standing Liberty silver quarters, and Walking Liberty, Franklin, and Kennedy silver half dollars. Success at metal detecting is never guaranteed. There are many variables, and you will benefit by preparing the search area months before the lesson in order to ensure that the students will acquire data that is reasonable for the allocated lesson time.
• Give the students graphing exercises that demonstrate their ability to set up and use a graph to represent a search area with coordinates.
1. Using two metal detectors (pre-checked for compatibility), have the students locate coins in the search area and place small flags representing "hits" for subsequent digging.
2. Pre-assign student groups a part of the search area to dig up and record each coins' date, depth, and precise location. Have the teams catalog all finds and mark their locations on their graph paper.
3. In the classroom, place each team's search gric under the transparency and mark the transparency with identifying symbols for each type of find with different colored Sharpies (during the data transfer, students compare their finds with others in the class). Have the students make hypotheses at this time.
4. Have the students analyze the data on different levels, such as:
• Social/geographic: patterns of coin loss in an area
• Circulation/economics: wear on coins versus time in the ground
• Soil science: depth of coins versus date
5. After group and class discussions, have the individual students draw conclusions and write them out.
6. Assemble the written conclusions into a poster that provides an overview of the project.
There are no modification options for this lesson plan.

Use the students' grids and records as well as post-project surveys and discussions to determine whether the lesson objectives have been met.

Games

This lesson plan is not associated with any Common Core Standards.

Discipline: Science
Domain: 5-8 Content Standards
Cluster: Science in Personal and Social Perspectives
Standards:

• Personal health
• Populations, resources, and environments
• Natural hazards
• Risks and benefits
• Science and technology in society

Discipline: Mathematics
Domain: 6-8 Data Analysis and Probability
Cluster: Develop and evaluate inferences and predictions that are based on data.
Standards:

In grades 6–8 all students should

• use observations about differences between two or more samples to make conjectures about the populations from which the samples were taken;
• make conjectures about possible relationships between two characteristics of a sample on the basis of scatterplots of the data and approximate lines of fit; and
• use conjectures to formulate new questions and plan new studies to answer them.

Discipline: Mathematics
Domain: 6-8 Data Analysis and Probability
Cluster: Formulate questions that can be addressed with data and collect, organize, and display relevant data to answer them.
Standards:

In grades 6–8 all students should

• formulate questions, design studies, and collect data about a characteristic shared by two populations or different characteristics within one population; and
• select, create, and use appropriate graphical representations of data, including histograms, box plots, and scatterplots.

Discipline: Mathematics
Domain: 6-8 Data Analysis and Probability
Cluster: Select and use appropriate statistical methods to analyze data.
Standards:

In grades 6–8 all students should

• find, use, and interpret measures of center and spread, including mean and interquartile range; and
• discuss and understand the correspondence between data sets and their graphical representations, especially histograms, stem-and-leaf plots, box plots, and scatterplots.

Discipline: Mathematics
Domain: 6-8 Measurement
Cluster: Apply appropriate techniques, tools, and formulas to determine measurements.
Standards:

In grades 6–8 all students should

• use common benchmarks to select appropriate methods for estimating measurements;
• select and apply techniques and tools to accurately find length, area, volume, and angle measures to appropriate levels of precision;
• develop and use formulas to determine the circumference of circles and the area of triangles, parallelograms, trapezoids, and circles and develop strategies to find the area of more-complex shapes;
• develop strategies to determine the surface area and volume of selected prisms, pyramids, and cylinders;
• solve problems involving scale factors, using ratio and proportion; and
• solve simple problems involving rates and derived measurements for such attributes as velocity and density.

Discipline: Science
Domain: 5-8 Content Standards
Cluster: Science as Inquiry
Standards:

• Ability necessary to do scientific inquiry
• Understand scientific inquiry