Introducing the idea of finding the middle for data sets – video

This week while I have been at Concord Consortium in San Francisco I have spent much of my time making videos of recent activities that use CODAP.  All of these activities I have been exploring with teachers and students in the work that I do.

Some of the earlier posts were about how to use CODAP:

This video explores a teaching and learning idea for introducing early ideas of median.  For New Zealand teachers this would be an activity I would do with curriculum level 3/4 students as they start to explore quantitative data and are looking for a signal as to the middle of the data that they have.  CODAP allows us to put in a movable line and using counts it can be moved until about half the data is sitting on each side.  I expand this to looking at the middle 50% of the data values and give examples of how to describe this.  As this is aimed at curriculum level 3/4 the examples describe the whole group (Kowhai Whanau Group).

If you want to explore the data set used in the video you can get your own CODAP document to work on by clicking here.  The data set used is a made-up data set using a random sample of students from CensusAtSchool.

Census At School 2019 data available now

Great discovery today when I went into the random sampler on Census At School, I found that the 2019 data base is there ready to use.  Big shout out to the team at Census At School and to all the teachers and their students who participated in the census.  Without all of the students there would be no data base, the teachers make this possible.

To find the database go to

Select download or explore a sample to see the new random sampler page which allows you to select the variables to explore without having to download and then tidy up the file before sharing.

Using CODAP for statistics and probability – a very quick start guide

On Saturday I presented a short topic at the Auckland Mathematics Association morning session on getting started with CODAP (Common Online Data Analysis Platform

Notes and links from the session can be found at

In addition there are three draft activities that I have been working on.  All three are part of a bigger lesson sequence so they need to be viewed with that in mind.

The first one looks at introducing measures of centre using CODAP.

The second one looks at a progression for scatter graphs, around curriculum level 5, using Q-plots to see if there is an association or not.

The third one is a look at posing investigative questions.