Why are they important?
You’ve heard the saying “A picture is worth 1000 words,” well it’s true! A graph can do this and so much more. Graphs are found everywhere, in magazines in newspapers and even seen on television because of their usefulness in helping to communicate information. Often times we do not have the time to read large amounts of text. Even then it is not certain that we will understand what we read. A graph can help us by presenting the information pictorially. Graphs are amazing tools that allow us to make information easy to look at.
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What is a graph?
A graph is a visual representation of one or more variables. They can be quick and direct and highlight the most important facts. Graphs can facilitate understanding of data and are easily remembered. There are many different types of graphs that can be used to convey information, including pictographs, tally charts, bar graphs, histograms, line graphs and pie charts. Depending on the data being represented some graphs are better suited to use than others. One can select the most appropriate graph using but not limited to the following guidelines: a pie chart (description of components), horizontal bar graph (comparison of items and relationships), vertical bar graph (comparison of items and relationships, time series, frequency distribution), line graph (time series and frequency distribution), scatterplot (analysis of relationships).
Knowing how to convey information graphically is important in the presentation of statistics and therefore there are a few guidelines one needs to follow when preparing them; facts must be visually accurate and show data without altering it. The display must attract the reader’s attention and compliment or demonstrate arguments presented in the text. Graphs must be correctly labeled and have a title.
Students should have a base knowledge of bar graphs, pictographs and circle graphs prior to starting this unit. If not, you can integrate the content of these brain and body lessons to drive the introduction of graphing in your math lessons. In their “I am Special” books the students will use this knowledge to graph their emotions, diet and academic progress.
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Graphing Lessons To Teach
The goal is to introduce the graphical representation of information. Graphing provides children with a powerful tool to make comparisons and represent numeric information extracted from a story problem. Students will be able to describe, organize and represent data in tables and graphs. The students will read and create picture graphs to record and analyze data. As students continue to collect data based on their healthy habits, daily nutrition and daily emotions they will create data tables, picture graphs and bar graphs to understand the data. Finally, students will be introduced to circle graphs and use this knowledge to explore comparison situations. Throughout, students will learn how to read picture graphs, tables and bar and circle graphs as they answer questions about them. Students will create tables and graphs while they consider the advantages and disadvantages of each form of data presentation. Objectives assessed will include reading and interpreting information from a table, picture graph, bar graph and circle graph, converting information from a table to a picture graph and a picture graph to a bar graph and solving comparison story problems.
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Picture Graphs
Students begin learning how to make a picture graph by using one circle to represent each piece of fruit that two friends in a story problem ate. Students learn how to label their graphs with the names of each friend in the story problem and how to give a graph a title. Organizing information into a graph and describing the information are key processes in learning to work with data.
Story Problem: Carla and Peter are trying to be healthy eaters. They know that it is important to fuel their bodies with fruit in order to stay healthy physically and emotionally. They also know that eating a variety of fruits will help them to become better learners. This week Carla ate 8 pieces of fruit and Peter at 5 pieces of fruit. Draw a picture graph to represent this data, and then answer the following questions.
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Carla ate more or fewer pieces of fruit than Peter?
How many fewer pieces of fruit did Peter eat than Carla?
Using Comparison Language
Students will solve comparison problems depicted in picture graphs. They use the comparative terms same, more and fewer as wells as greater, less than and equal symbols to compare the information in the graphs. Since the pictures in the rows or columns of the picture graph are aligned they can be easily compared to find how many more or how many fewer items would equalize the groups.
Introducing Tables
Students will construct tables with rows, columns, headings and numbers. Students will see how they can easily compare information when it is organized into a table. Students will have the opportunity to convert tables to picture graphs and pose and answer questions about all of these data formats.
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Introducing Bar Graphs and Circle Graphs
Students will move from picture graphs to bar graphs as they learn to convert a picture graph to a bar graph by shading the squares that have pictures in them. They change the numerical scale to the number line length model with numbers at then end of each square telling how many so far.
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Students will read information in bar graphs and pose and solve problems using information in the bar graphs. Students will read and create bar graphs in both horizontal and vertical form.
Students will learn how parts of a circle and the size of the parts can represent different information and values. They complete a circle graph using information from a bar graph. They compare bar graphs and circle graphs and find how each can be used for different purposes.
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Students will use this basic understanding of graphs
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to create their own tables and graphs in their “I am Special” book. They will chart their daily food intake and their daily emotions. They will record this data for four weeks. During that time the teacher will also supply them with test scores ie. weekly math and spelling tests as well as monthly running records and comprehension quizzes in reading. The students will then create pictographs or bar graphs to visually show what they ate, how they felt and their academic progress. Individually and as a class (names will be removed from the graphs), the students will analyze the total data and look for correlations between what they ate and how they performed in school.
