Course Guide - USAID Teacher Education Project

3. What is essential to know or do in class?a) Building on what students have learned informally about data tables when creatingtally charts for categorical data, introduce the necessity of putting numerical data innumerical sequence to show patterns, both numerical and visual (to show the shape ofthe data).b) Introduce the concept of range.c) In order to introduce the mode, have students read and analyse several charts andgraphs to see how the mode appears in various data displays.d) Provide opportunities for students to ask questions about multi-modal graphs.e) Introduce the concept of the median and have students use three methods to findthe median of a data set.f) Provide students with opportunities to analyse situations in which the median ispart of both odd and even numbered data sets and where the median is not an integer.g) Note that both the mode and the median (not just the arithmetic mean) are"averages" that show what is "typical" about the data set.4. Class Activitiesa) Frequency Tables: To build on what students have learned informally about datatables when creating tally charts for categorical data (and function tables in theAlgebra unit), use the Frequency Table & Mode handout to introduce the necessity ofputting numerical data in a numerical sequence (either ascending or descending).This will allow students to discern both numerical patterns and the shape of the data.b) Ask students how they would describe the range (or spread) of their name-lengthdata that they recorded in their notebooks. Note if they use the conversational("from".... "to"....) format or if they suggest a formula they learned: subtract thelowest value from the highest value.Discuss how both strategies are valid, but that one is more conversational and theother more formally mathematical.c) Introduce the mode by having students refer to the "name length" line plot and bargraph they created last week. Which number of letters has the highest “stack of x's” inthe line plot, and the highest bar on the bar graph?If there is only one answer to this question, this number is the mode. If there are morethan one stack/bar with the same highest frequency, the data set is multi-modal (bimodalif there were two). Emphasize that the mode is the data that occur mostfrequently in a given data set.