Learning goals: Teacher Facing Calculate the range and interquartile range (IQR) of a data set and interpret (orally and in writing) what they tell us about the situation. Comprehend that “interquartile range (IQR)” is another measure of variability that describes the span of the middle half of the data. Identify and interpret (in writing) the numbers in the five-number summary for a data set, i.e., the minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 6.8 Data Sets and Distributions, Grade 6.