5.4. Median http://www.ck12.org
To begin the class, refer to the comments on the measures of central tendency that were recorded from the earlier
concept, when the brainstorming session occurred. Highlight the comments that were made with regard to the
median of a set of data and discuss this measure of central tendency with your classmates. Once the discussion has
been completed, choose a handful of blocks like you did before, with your classmates doing the same.
Next, form a line with your classmates as a representation of the data from smallest to largest. In other words, those
with the largest number of blocks should be at one end of the line, and those with the fewest number of blocks should
be at the other end of the line. Have those at the ends of the line move out from the line 2 at a time, with 1 from each
end leaving the line at the same time. This movement from the ends should enforce the concept of what is meant
bycenter, and as you and your classmates move away, you will see that the last 1 or 2 people remaining in the line
actually represent the center of the data.
A similar activity can be done by using the grid paper chart. Instead of you and your classmates moving from a line,
you could simply remove your post-it notes the same way.