# 2.15 - Graphs

The student will

a) collect, organize, and represent data in pictographs and bar graphs; and

b) read and interpret data represented in pictographs and bar graphs.

### BIG IDEAS

• So that I can make sense of data which is presented in a graph, pictograph or chart format
• So that I can understand that the reason we study data is to find answers to questions and decide what to do next
• So that I can  show and compare data. through pictures in pictographs
• So that I can understand that data can be shared through pictures, not just numbers. Pictographs are graphs that use symbols to show and compare information
• So that I can understand that all types of graphs are used in everyday life and cross curricular content. It is useful in Math, Science, Social Studies, English, Health, Physical Education, Economics, etc

### UNDERSTANDING THE STANDARD

• Data can be collected and organized in pictographs and bar graphs.
• The purpose of a graph is to represent data gathered to answer a question.
• At this level, the number of categories on a pictograph should be limited to four when a student is creating a graph, and six when a student is interpreting and analyzing a graph.
• A pictograph uses pictures or symbols to represent one or more objects (data points).
• A key is provided in a graph to assist in the analysis of the displayed data.
• The key should be provided for the symbol in a pictograph graph when the symbol represents more than one piece of data (e.g.,    represents five people in a graph).  At this level, each symbol should represent 1, 2, 5, or 10 pieces of data.
• An example of a pictograph is:
The Types of Pets We Have

 Cat Dog Horse Fish

=  2 students

• In prior grades, students worked with simple pictographs with a scale of one (i.e., each picture represented only one item) making a key unnecessary.
• Students’ prior knowledge and work with skip counting helps them to identify the number of pictures or symbols to be used in a pictograph.
• Definitions for the terms picture graph and pictographs vary.  Pictographs are most often defined as a pictorial representation of numerical data. The focus of instruction should be placed on reading and using the key in analyzing the graph.  There is no need for students to distinguish between a picture graph and a pictograph.
• Bar graphs are used to compare counts of different categories (categorical data). Using grid paper may ensure more accurate graphs.
• A bar graph uses horizontal or vertical parallel bars to represent counts for several categories. One bar is used for each category, with the length of the bar representing the count for that category.
• There is space before, between, and after each of the bars.
• The axis displaying the scale that represents the count for the categories should begin at zero and extend one increment above the greatest recorded piece of data.  In grade two, students should collect data that are recorded in increments of whole numbers limited to multiples of 1, 2, or 5.
• At this level, the number of categories on a bar graph should be limited to four.  A key should be included where appropriate.
• Each axis should be labeled, and the graph should be given a title.
• Statements that represent an analysis and interpretation of the data in the graph should be discussed with students and written (e.g., similarities and differences, least and greatest, the categories, total number of responses, etc.).
• Data gathered and displayed by students should be limited to 16 or fewer data points for no more than four categories.  However, students at this level should be able to interpret graphs that contain data points that represent their entire class (e.g., approximately 25 data points).

### ESSENTIALS

The student will use problem solving, mathematical communication, mathematical reasoning, connections, and representations to

• Collect and organize data using various forms of data collection (e.g., lists, tables, objects, pictures, symbols, tally marks, charts). Data points, collected by students, should be limited to 16 or fewer for no more than four categories. (a)
• Represent data in pictographs and bar graphs (limited to 16 or fewer data points for no more than four categories). (a)
• Read and interpret data represented in pictographs and bar graphs with up to 25 data points for no more than six categories (represented horizontally or vertically). State orally and in writing (at least one statement) that includes one or more of the following:
• Describes the categories of data and the data as a whole (e.g., adding together all data points will equal the total number of responses);
• Identifies parts of the data that have special characteristics; including categories with the greatest, the least, or the same;
• Uses the data to make comparisons; and
• Makes predictions and generalizations. (b)

### KEY VOCABULARY

Updated: Aug 22, 2018