**Second Look - Measures of Central Tendency** |

Mathematical Exploration: Mean, Median, or Mode: Which One Is My Pencil? Students measure pencils and explore mean, median, and mode in the process. |

Contemporary Curriculum Issues: Statistics in the Middle Grades: Understanding Center and Spread
Understanding center and spread in statistics is the focus of this issue's Contemporary Curriculum Issue. A lesson is described that involves formulating a question that can be answered with data, collecting data to address the question, analyzing the data and interpreting the results. The mean is viewed as a balancing point to discuss variability in dot plots and box-and-whisker plots.
This regular department provides a forum to stimulate discussion on contemporary mathematics curricular issues across a K-12 audience. |

It’s a Fird! Can You Compute a Median of Categorical Data? Students
need time and experience to develop essential understandings when they explore
data analysis. In this article, the reader gains insight into confusion that
may result as students think about summarizing information about a categorical
data set that is attempting to use, in particular, the median. The authors
highlight points to consider in helping students unpack these essential
understandings. |

Illuminations Lesson: Building Height
Students will use a clinometer (a measuring device built from a protractor) and isosceles right triangles to find the height of a building. The class will compare measurements, talk about the variation in their results, and select the best measure of central tendency to report the most accurate height. |

Data Analysis and Probability Standard for Grades 6-8
In grades 6–8, teachers should build on this base of experience to help students answer more-complex questions, such as those concerning relationships among populations or samples and those about relationships between two variables within one population or sample. Toward this end, new representations should be added to the students' repertoire. Box plots, for example, allow students to compare two or more samples, such as the heights of students in two different classes. Scatterplots allow students to study related pairs of characteristics in one sample, such as height versus arm span among students in one class. In addition, students can use and further develop their emerging understanding of proportionality in various aspects of their study of data and statistics. |