You will collect data, and construct and interpret it in a tally chart.
After completing this tutorial, you will be able to complete the following:
Tally charts and frequency tables are typically the first data-gathering visual that students learn how to use. These types of graphical representations are the foundation for more complex graphs such as histograms. Be sure students understand that each tally mark represents one data point.
The following key vocabulary term will be used throughout this Activity Object:
· Frequency: The number of times a specific data point occurs.
The following numbers were rolled on a die:
1, 2, 3, 1, 2, 6, 2, 5, 1, 2, 6, 3, 2
We can see that several numbers were rolled more than once. By creating a frequency table, the data points are quickly organized so that it is evident which number was rolled most often.
A frequency table is constructed by arranging collected data points (in ascending order of magnitude) with their corresponding frequencies.
We use the following steps to construct a frequency table:
1. Construct a table with three columns. In the first column, write down all of the data values in ascending order of magnitude.
2. To complete the second column, go through the list of data values and place one tally mark at the appropriate place in the second column for every data value. When the fifth tally is reached for a mark, draw a diagonal line through the first four tally marks as shown for "Number Rolled = 2" in the above frequency table. We continue this process until all data values in the list are tallied.
3. Count the number of tally marks for each data value and write it in the third column.
Tally charts are used for small to medium samples of data, generally under 50 data points. When displaying larger sets of data points, recording each tally mark could take too much time and result in a tally chart that's difficult to read. Emphasize that larger data sets are more effectively displayed using other types of graphs and charts.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Students should know the definition of frequency.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||frequency, tally chart, data collection|