Illinois State University Mathematics Department
MAT 326: Technology Tools for Secondary School Mathematics Dr. Roger Day (day@ilstu.edu) 
Session #5 
Warming Up: Free Rice, Anyone? or Algebra Problem of the Day
New Groups via SmartBoard shakeup.
A Problem to Explore: College Laundry
My son Avery is about to begin his first year in college. Among all the other things he has to think about is laundry! At Drexel University in Philadelphia, students can use the washing machines and dryers in their dorms free of charge. They even have a SmartPhone ap that will signal them when a batch of clothes is done.
Students do, however, have to provide laundry detergent, and, as he was browsing the web, my son got some interesting suggestions about doing laundry in college. Among others was this:
"I use a liquid laundry detergent, and every time I fill the cap with the required amount of detergent, I add back to the container a halfcap of water! This helps me extend the detergent and save me some money along the way. Give it a try."So one of our dinnertime conversations a week or two ago was about this suggested practice. Of course, we wanted to mathematize the whole situation! Here are some of the questions that emerged from our discussion:
 Could this be a worthwhile practice? What comments and concerns immediately come to mind?
 What sorts of calculations could you carry out to determine whether this was a worthwhile practice?
 What are some of the variables inherent in this practice that we need to identify in order to create a mathematical model for it?
Phase I Exploration
In your small group, explore the mathematics of this situation and try to create a model for the addback process. Take notes and record your attempts, results, questions, and road blocks. Be ready to share your efforts with the rest of the class.
Phase II Exploration
Continuing in your small group, ask me for the College Laundry Phase II Exploration guide. Follow the instructions, again keeping accurate, detailed, and specific notes of your results.
Spreadsheet WarmUps: Work through these practice sets in groups of no more than three people.
 Set I
 Call up this Excel file (excelbasics01). With this Excel file open, open and view the following videos, in the order shown. As you view each video, modify the spreadsheet that you also have open. It will often be necessary to pause or replay the video!
Quadratic Explorations: Group Work to Return with Comments
 Set II
 Create one spreadsheet file to contain a separate tab (sheet) for each of the following situations.
 Create a spreadsheet that will allow a user to enter the coordinates of two points (ordered pairs) and the spreadsheet will then show two equations for the line containing those two points, including the pointslope form for a line and the slopeintercept form. Look at the video here for a guide to the format of your spreadsheet file. Name the tab (sheet) Linear Equation.
 Create a spreadsheet that will allow a user to enter a value for which a square root approximation is desired and the spreadsheet will then show the steps of Newton's Method in determining that approximation. Look at the video here for a guide to the format for this spreadsheet file. Name the tab (sheet) Newton's Method.
 Create a spreadsheet that will allow a user to enter the numerical coefficients of any fourthdegree polynomial together with a specific value of x and the spreadsheet will show an approximation for the numerical value of the derivative of the polynomial at the specified point. Look at the video here for a guide to the format for this spreadsheet file. Name the tab (sheet) Polynomial Derivative.
 When all three tabs (sheets) are complete in one file, name the file as follows: 326SSwarmup01name, where "name" is replaced by the last name of the person in your group who would be listed first in an alphabetized list of last names. Attach that file to an email and send it to me with the subject line, "Spreadsheet WarmUp #1" (no quote marks). At the top of your email message, show the first name and last name of each person in your group.
Mobile Apps: A Preview
Here's an example of an iPad app that a school mathematics teacher might use.
Assignments for Session #6 (24 Sept 2012)
 Complete the Spreadsheet WarmUp activities as described above, through the first item in the Set II spreadsheets, Linear Equations. Requirement: Spreadsheet file submission by email, due Saturday, September 22, by 9:54 pm. Note that one submission is required per group! Each group member, however, should retain a copy of the Excel file.
 Continue to look for and critique mobile apps that focus on school mathematics, preferably secondary school mathematics. More info on this to follow.
 Search for an online warmup activity to share with others. Details to follow.

Next
Session 

Here is the guide for Phase II
of the College Laundry Problem.
(a) How did this spreadsheet help or hinder your exploration of the problem?
(b) What improvements, modifications, or corrections to the spreadsheet would you suggest that would help your exploration?
Include names of all your group members and submit your written work (3,4,5,6 above) to me, into my grubby little paws, tonight!