# Middle School Math Lessons | Using Excel in the classroom

Most adults only think of Microsoft's Excel as a program for creating spreadsheets. Excel, though, has been used in classrooms all across the country in a variety of creative ways.

Can a computer program motivate math students weary of "drill and kill"? Teachers all over the country use Microsoft Excel in ways that excite students about the power of math in everyday life. Education World spoke with Illinois middle school teacher Kelly McMahon about three important roles Excel plays in her seventh- and eighth-grade classrooms. Included: Samples of student work, ideas from other teachers, and practical Web sites to help teachers get started using Excel in their own classrooms.

"I have always been interested in bringing visual, hands-on activities into my classroom," said math teacher Kelly McMahon, who is also assistant principal and technology coordinator for St. Joseph School in Libertyville, Illinois. "I use Excel regularly in my math classes, and I love it!

When McMahon transferred to St. Joseph School from a school in which computers were not available, she dived right into the Excel lessons integrated into Gateways to Algebra and Geometry (McDougal, Littel, 1997), a middle-grades math text. "That textbook helped me get started," McMahon told Education World. "I went from there and found ways to expand using Excel. I use it to teach and reinforce math concepts. It is a powerful teaching tool."

McMahon uses a projection device to introduce a concept and demonstrate a technique on Excel. "Excel is a great way of introducing the idea of variables and setting up equations," McMahon told Education World. "When you set up an Excel spreadsheet, you are not really working with numbers. You are working with variables -- referencing 'cells.'"

One of McMahon's favorite concept lessons involves square roots and squaring. "I start with a negative number and create an ascending list of numbers," said McMahon. "Then I use Excel to chart the square roots and squares. When you take the square root of a negative number, Excel gives you an error. I ask my students, 'Why do we get an error in that cell?'

"When I graph our results [see graph at the right] we are able to see that up to the number 1, squaring a number gives a lesser result than taking a square root. After 1, the squares become exponentially greater than the square roots. We can talk about intersection and exponential growth."

SOLVING PROBLEMS WITH EXCEL

"I also use Excel to demonstrate how to solve problems with repeated change," McMahon told Education World. "To teach percentages is one thing, but to give an application and be able to forecast change is a powerful lesson."

One example of a whole-class lesson McMahon uses is creating a balance and spending spreadsheet. Students may begin with a balance of \$20,000 in a trust fund. They chart \$2,000 annual deposits and withdraw 25 percent of the balance each year. "What's going to happen to the balance?" McMahon asks her students. "When will the balance and the spending level off?"

"We can forecast that with the click of a button -- it's a piece of cake!" McMahon told Education World.

REAL-WORLD STUDENT PROJECTS

After a several-week unit on graphing, McMahon's students are ready to use Excel to pursue individual, real-world research projects.

"I start them out with some examples," McMahon said, "such as a survey about favorite food or plotting changes in the Olympic high-jump record over the years. I ask my students, 'If the upward trend continues, what will happen to the high-jump record in 2020?'

"With my seventh graders, we just extend the line," McMahon explained. "With eighth graders, we actually do a linear regression, find the equation of the trend line, and plot it. With Excel, you create a spreadsheet, make a scatter plot, and get a trend line with its equation. In the Olympic high-jump record example, our own analysis of the data and our own conclusions would reflect the idea of human limitation and how it might influence the upward trend.

"I focus on drawing conclusions," McMahon stressed. "It is wonderful that the students produce a spreadsheet and a graph, but I want to know what it tells them. Can they analyze the data and tell the class something about it? That's what I want to know."

"Drawing trend lines on a graph really helped to show the information of my project," said Mark, an eighth grader.

McMahon's students have pursued a variety of interesting individual topics, including obesity trends in the United States, roller coaster height and maximum speed, and numbers of goals scored in World Cup soccer [see graph at the right or click here to download the Excel file].

"When we are working along and a graph pops up, I get a chorus of 'cool!'" McMahon laughed. "The expressions on their faces, how on-task they are -- that says enough for me! I know they are motivated and they're learning."

"I really enjoy using Excel for math projects," said Allison, an eighth-grade algebra I student. "You can see patterns in your work, and it combines technology with everyday math."

McMahon is gratified that her students use Excel to go beyond what their homework requires. "They use Excel on homework problems when it might have been quicker to do the problem with paper and pencil because they are interested to try it out and see what happens," McMahon said.

"The best thing I tried using Excel for was the graphing feature when I am doing my math homework," agreed Lisa, another eighth grader.

"They are seeing the power of the spreadsheet, and learning when and when not to use it. Their homework probably took them a little longer, but they think, 'Gee, how could I do this on Excel?' I think that really says something!"

Another example of a great Excel project is Bloomington (Illinois) Junior High teacher Kimberly Hall's housing prices and costs unit. "My students track and graph real-world statistics on Excel, exploring mortgage costs at different rates for different time periods," said Hall. "They use the real estate section of our local newspaper online to compare housing costs within our county." Hall's housing budget project is integrated with a language arts unit investigating careers and salaries.

Excel math units can easily complement other disciplines, such as science, in which students collect and analyze data, develop a mathematical model to explain their data and make predictions.

Article by Leslie Bulion

Education World®