## Data and Graphing

Organizing Data
Collecting, organizing, and interpreting data are common real-life activities. It is important to present the data in a way that makes interpretation easy.

There are many forms in which data can be organized and presented. Whether to use a tally chart, a bar graph, a picture graph, or another graph depends on what data one wants to display. If a child is collecting data in order to find which of three activities is the favorite of twenty children, it would be appropriate to make a tally chart, making a mark for each response as the survey is being taken or as the slips of paper with the responses are counted. To simplify the counting of tally marks, children should be taught to cross each group of four with another tally mark to make a group of five tally marks.

Pictographs
A pictograph represents data with pictures. For example, a picture graph could be used to show how many bears are in a zoo. Pictures of bears can be shown on the graph to represent the numbers of bears. The title tells what the graph is about.

At this grade level, each picture represents 1 object. In future grades, children learn that each picture can represent 2 or more objects. When this is the case, a key to the pictograph shows how many objects each picture represents.

Bar Graphs
A bar graph is used to display data that can be counted. On a vertical bar graph, the horizontal scale along the bottom of the graph shows what is being counted, and the vertical scale at the left shows the number counted. On a horizontal bar graph, these scales are reversed. For example, one scale may list several animals chosen by children as being their favorite. The other scale may be numbered 0, 1, 2, 3, 4, and 5. The lengths of the bars would represent the number of children that chose a particular animal. Bar graphs simplify the process of comparing data.

Teaching Model 4.2: Read a Pictograph