Course Guide - USAID Teacher Education Project

4. Class Activities:a) Begin by reminding students of what they learned in the algebra unit about discretevs. continuous graphs. Note that the four types of graphs being studied today are alldesigned to display discrete data.b) Have students recall how they used tally marks to record data and create a bargraph in the last class session. Note that in the prior session the emphasis was onconstructing a graph, but that it is equally important to be able to read and analyse agraph and raise questions about what the data imply.Without giving any further directions or comments, have students work in pairs todiscuss the graph analysis sheet. What comments and questions do you notice as youcirculate about the room? Call the class together for a whole group discussion of theirthoughts.On the pictograph, did they notice the key and the distortion caused by the varyingsize of the icons? How many responses were represented on this graph? Could thisbe a chart about pets? Or about favourite animals? How might 125 horses berepresented?For the bar charts, ask if they thought the double bar graphs were clear. How didcolour contributed to communication?What was their first impression when looking at the favourite food graphs? What didthey notice on further analysis when comparing them? What is an approximatenumerical difference among the three bars? How did the displays either represent ormisrepresent the data? Why did this occur?Line plots may be a new type of display to some students. Ask them what the datamight be representing. How does the lack of a title or labels affect theirunderstanding of what the graph means? What do they notice about the shape of thedata? If students do not use terms such as range, minimum, maximum, outlier,cluster, gaps, etc., be sure to use them in your own description of the graph. Did theynotice that the base of the graph was a segment of a number line? Ask if the databeing shown was categorical or numerical.c) While still working with the whole group, begin the following activity that willresult in the creation of a line plot. Ask the students to count the number of letters intheir first and last names. To illustrate how raw data needs to be organized, pollstudents individually (rather than have them raise their hands if they had a certainnumber of letters in their names). This should result in a disorganized list of data.How do students suggest the data be organized in order to translate it to a line plot?Once this has been determined, ask what they would suggest for the range of numbersdisplayed on the number line segment. Should they begin at 0 or some othernumber? How far do they need to go? How far would make a good display? Drawthe number line segment they suggested on chart paper. Then have each student comeup and put his or her "x" atop their number. Do students realize that in order for the