Salt: The Essence of Life
Multidisciplinary Curriculum for Students
Unit 10: Economics
Differences in Prices
2 Class Periods
Overview
This module focuses on how different factors can influence the price of salt. Students will discover that salt has many different forms and has a wide range of prices. These prices are dependent on a variety of economic principles.
Background
Salt is produced in three ways: by vacuum evaporation of brine, mining of rock salt and by solar evaporation of seawater or brine. It comes in many commercial forms including: table salt, road salt, water softening salt, and block salt for animal nutrition. Each type of salt may have a different production process, shipping mode, and packaging design. The various forms, as well as supply and demand, effect its price. This lesson allows students to find the differences in the price of a product, and the reasons behind the price even when the basic product is the same.
Getting Ready
Time: 2 class periods
Materials
Photocopy Student Page: Salt Price Comparisons, and distribute to students.
Instructions
Instruct students to conduct salt price research via store visits, literature research, and telephone interviews.
Activity
1. Ask students to name the different types and commercial forms of salt that they have seen. List these on the blackboard. Your list should include deicing salt, table salt, water softening salt, and salt for livestock.
2. Ask your students to research the price of each type of salt. Develop a plan on how to obtain this information. Keep in mind that different venders will have different prices, so get prices from several different sources.
3. Assign students the task of getting price information for a specific type of salt, or have them work in small groups to gather the data. As a class, complete the table on the attached student page.
4. After completing the chart, analyze the data as a class. Note the differences in price between types of salt products, vendors, quantities and whether it is in bulk or packaged form. Ask students for possible explanations for such price differences.
Assessment
To get a better idea of why differences in price exist between the types of salt products, students should think about production processes, packaging, energy costs and shipping methods and distances. Have the students write a paragraph about the different production processes and the pricing of salt. For example, table salt undergoes more production processing steps than deicing salt.
Conclusion
Have a class discussion about the principles of supply and demand. Why would deicing salt be more expensive during an unusually severe winter with lots of snow? Why would it be cheaper during a milder winter? Price differences exist between salt bought in large bulk quantities and salt bought in small quantities and in packaged form. Why?
Student Page: Salt Price Comparisons
| Vendor #1 | Vendor #2 | Vendor#3 |
| Per Ton | Per Pound | Per Ton | Per Pound | Per Ton | Per Pound | |
| Deicing salt (Bulk) | ||||||
| Deicing Salt (prepackaged) |
||||||
| Table Salt | ||||||
| Water Softening Salt | ||||||
| Agricultural Salt (loose) | ||||||
| Agricultural Salt (block) | ||||||
| Other Types of Salt (ex. Ice Cream, Pickling) |
* Where to call to obtain price information:
Deicing Salt (bulk) - city, county or state
Highway Department
Deicing salt (packaged) - Grocery Store,
Hardware Store
Table Salt - Local Grocery Store
Water Softening Salt - Hardware Store, Gas
Station
Agricultural Salt (block or loose) - Feed or
Livestock Store, Hardware Store
** Note One Short Ton = 2,000 Pounds (lbs.) = 32,000 Ounces (16 oz/lb) = 907,168 Grams
(28.349 grams/oz)