Measures of Center

Measures of Center

What students learn

Students learn that mean, median, and mode are different ways to describe the center of a data set. Start with Mean Describes the Center of the Data to hear the idea in the simplest form.

Why it matters

Different data sets can have different centers, so students need more than one summary number. Watch Median Finds the Middle Value to see why ordering the data matters.

Learn the idea

A single outlier can change the mean, but not always the median or mode. Mode Needs Context and Careful Checking reminds students to ask what the data are really saying before they choose a summary.

Try it

Give the student a data set such as 3, 4, 4, 6, 9, and 20. Ask them to find the mean, median, and mode, then decide which value best describes the center and explain why.

Parent guide

Keep the discussion concrete. Ask the student to order the numbers first, talk about the middle, and notice when one unusually large value pulls the mean away from the rest.