A “Buzzing” Introduction to Significant Figures


ENGAGE: A “Buzzing” Introduction to Significant Figures

Education “buzz words” can be meaningless jargon, or they can challenge us to consider new approaches to teaching and learning. Don’t let the jargon be a buzz kill!

“Significant figures are so confusing,” says my former student, who is currently taking AP Chemistry. My PowerPoint lecture with lab to follow didn’t work. Convicted, I wrestled with transforming my tired lesson. I embraced the buzz words. Let’s look at a significant figures lesson that changed my compliant, quiet learners to ENGAGED COLLABORATORS.

What Works for Me:

Step One: The Night Before the Lesson—Students preview the content digitally from home.

A well-planned digital lesson saves class time by skipping the passive note-taking phase. Also, students control the pace of delivery allowing for repeats and pauses.

[Buzz Words: Flipped Classroom, Technology Integration, Blended Learning]

  • Brainstorm a mastery “wish list”. “In a perfect world, my students could ______ significant figures.”
  • Create a concise PowerPoint that introduces each wish list idea at a basic level. It may be frustrating to leave out details. Remember that you want students to watch your entire video, so that means keeping it short. Consider providing a graphic organizer or outline to guide students in note-taking.
  • Choose your favorite screencasting software or app to record your voice over the PowerPoint. Ask your media specialist for help!
    • Confession - I’d never heard of screencasting until last year.
    • Definition: a program that records your voice and your computer screen creating a video
    • Examples:
      • “Explain Everything” - free app for iPad and Android tablets that records your voice and your screen. The app allows you to write on the screen as you speak. You can find several “how to” videos on YouTube.
      • “ScreenChomp” - free iPad app that allows you to upload pictures and record your voice and writing on the images. (I started here.)
      • “Camtasia” - expensive, powerful software that can be purchased to record, edit, add music, etc. (I use this now, but I don’t know how to use all of it’s bells and whistles.)
  • Post the video to your digital platform of choice. Edmodo is a simple, intuitive platform, and I began there.

Step Two: First 30 Minutes of Class—Students apply prior knowledge of measuring, recording data, and calculating with measurements.

[Buzz Words: Flexible Grouping, Real-world Application, Active Learning, Data Collection, Student Collaboration]

  • Stake out five rectangular plots of land of various sizes. Name each plot for communication purposes. Warning - In case of bad weather, search online for images of aerial plots to print and use indoors.
  • Build homogeneous groups of 4 to 6 students using recent performance data. Admittedly, I teach this lesson on the second day of class so my recent performance data is minimal.
  • Invite student groups to construct a data table to record the measurements needed to:
    • Fence the plot using pre-fabricated fencing sold by the meter
    • Landscape the plot using squares of sod sold by the square meter

Note - My students struggle to construct data tables. I normally move from group to group checking and suggesting revisions to the data tables before they get too deep in data collection.

Plot Name
  • Instruct students to begin another data table and measure a second plot.

Step Three: Next 30 Minutes of Class—Teacher facilitates students’ discovery of the need for rules in making measurements and rounding answers.

[Buzz Words: Inquiry Learning, Data Collection, Data Analysis, Student Collaboration, Formative Assessment, Identifying Similarities and Differences]

  • Return to the classroom where student groups sit together.
  • Ask students to add two columns to each of their data tables for a comparison group and accepted value, respectively. Facilitate student collaboration, asking groups to share data with other students who measured the same plots. Each student should end with initial, comparison, and accepted data for two plots. The accepted values should follow significant figure rules for an estimated digit and rounded answers.
Plot Name Comparison Accepted
  • Invite student groups to analyze the data by comparing and contrasting the three sets of data: their own, the comparison group, and accepted. Give hints to consider decimal places and units. Facilitate a quick sharing of similarities and differences with the whole class.
  • Encourage each group to brainstorm suggestions for getting more consistent data between groups. Ask the question: How can we increase our similarities list and remove all of the differences?
  • Call the class back together, and ask groups to share one or two suggestions. FInally, draw the conclusion that specific rules are needed for making measurements and rounding answers to increase consistency between scientists’ data.

Step Four: The Night After The Lesson—Students review significant figure rules digitally and answer three questions online.

[Buzz Words: Technology Integration, Blended Learning, Formative Assessment, Diagnostic Data]

  • Construct a three-question online quiz using your digital platform or a Google Form.
  • Ask students to review last night’s video lesson with focus on learning three skills:
    • Measure correct using an estimated digit
    • Round addition and subtraction answers
    • Round multiplication and division answers
  • Instruct students to apply the learning on the online quiz by midnight. You can review the quiz data before class to adjust your instruction or form flexible groups.

If you are interested in my differentiated follow-up lesson, check out my next post, “Post-Inquiry Activity: A Tiered Significant Figures Lesson.”