Math Investigations

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Chapter 1

Part 1: Home and School Investigation

Send the Letter to Family (PDF file) home with each child. Then hold up a toy and ask children to place it in a group. Use the following list of ideas to sort the toys:

  • size
  • color
  • kind of toy (toy cars, dolls, and so on)

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 5 on sorting by your own rules.


  • many different kinds of objects

Introducing the Investigation

Gather a group of at least six objects that you could easily sort into two groups. For example, you might find objects that are red and objects that are yellow. Explain that you are going to sort the objects and you want them to think about how you are sorting them. Tell the children to raise their hands when they know how you are sorting the objects. Ask them not to say anything at this point. Then sort the objects into the two groups. Ask a volunteer to describe how you sorted the objects. Ask the children to point out objects that would go in one group or the other and objects that would not go into either group.

Doing the Investigation

Gather another group of objects that would be easy to sort. Ask a volunteer to come up and sort them into two groups. Have the volunteer whisper into your ear how he or she plans to sort the objects. You can make sure the sorting plan is a good one and help the volunteer sort. Have the children watch as you sort and follow the same procedure.

Repeat the activity with different volunteers.

Extending the Investigation

  • Do the same activity, having children sort objects into three or more groups.

Houghton Mifflin Math Grade K