Exploring Data:
A Develop Understanding Task
This task has no fixed student sheet. It makes use of the Exploring Data PowerPoint
(ExploringData.ppt)
Exploring Data: – Teacher Notes
A Develop Understanding Task
Purpose: This activity models an activity designed by Steven Leinwand (author of Accessible
Mathematics). The mathematical goal of this activity is to make sense of the data. It should surface
student thinking about what data in tabl
Materials needed:
Exploring Data.ppt: PowerPoint display of a two-way table, slowly revealing itself
 Before leading the task, be sure you have previewed the PowerPoint.
Core Standards Focus:
Related Standards:
Launch (Whole Class):
Show the PowerPoint that displays a partially filled out table. Each subsequent slide adds a bit more data
to the table. Show one slide at a time, letting participants guess what might belong in the missing cells,
and what the data might represent.
Explore (Small Group):
Accept all possible responses. Continue to add information to the table bit by bit as participants refine and
explain their conjectures until the final piece of information is revealed.
Discuss (Whole Class):
1. Before the column and row labels are added, emphasize the importance of context.
What is in the missing cells?
What might the data represent?
What can be discovered from the table?
What do you need to know in order to understand the table?
Listen for ideas about the necessity of unit labels, and table percentages. Without context
the data tends to be meaningless. Context is important – gives relevancy to data! Share
participants’ ideas and share work that brings out upcoming topics on table percentages,
units of measure, and comparisons between categories.
2. What did you find you NEEDED to know in order to understand the table? (units of measure,
column and row labels, etc.)
3. Reflect on the Practice Standards that were employed in the activity (1, 3, 6 & 7), specifically
attending to precision in mathematical language.
4. Introduce the idea of how mathematical language may differ from common usage. The Mean
Teacher comic illustrates this and is at the end of PowerPoint. (This issue should be revisited
throughout the day, for example in the discussion of “and” and “or” in probability.)