# Lesson 12

Variability

These materials, when encountered before Algebra 1, Unit 1, Lesson 12 support success in that lesson.

### Lesson Narrative

The mathematical purpose of this lesson is for students to recall how mean absolute deviation can be used to understand more about situations. In the associated Algebra lesson, students will begin the change from using mean absolute deviation to the more mathematically useful standard deviation. Although the values of those measures of variability are different, interpreting their relative values is very similar. Students reason abstractly and quantitatively (MP2) when they compare situations using statistics and data displays. Students make use of structure (MP7) when they notice similarities between box plots for a given situation.

### Student Facing

- Let's understand variability in situations.