Lesson 2



LESSON 2.  Investigating a Problem (Lab)


Objective: Students investigate what brand of paper towels is the most cost effective.


paper towels (various brands)

2 lb coffee can

400ml beaker


clear plastic cup (8 oz)

triple beam balance or electronic scale

rubber band

mass weights




Teacher Notes:

Money is important to our society.   Many students may not realize that economists study how money impacts societies.  Economists use math theory to develop ways in which countries operate.   In this lesson, students perform an analysis of paper towels to see if they can find the best buy for a school.  They need to incorporate the scientific method in research and making conclusion on the data derived.

Students will be testing multiple brands of paper towels to determine which type is most absorbent, the strongest, least expensive to use, the best combination of these and finally, which type is the best to buy, taking all of these results in to consideration. 

Rather than giving students the variable to be tested and how they are to be tested up front, it is best to lead them to these variables with questions such as, “What is important to you when using a paper towel?” Make a list from their answers but select strength and absorbency as possible key variables.  It will be helpful for students to have access to calculators in order to complete the cost analysis.

In times of budget concerns, one very valuable aspect of the lab is the students will determine if the school brand of towel is really cost effective for the school or district to be purchasing.  A medium sized district (4000 students) can easily spend $10,000 -15,000 a year on paper towels.

You may want to substitute paper towels with toilet paper especially if your school uses multi or single fold towels paper towels.  You also might make this exercise more related to brands they would use at home, so the students can report to their parents about the best buy.


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