Math Investigations

Help with Opening PDF Files

Chapter 5

Part 1: Home and School Investigation

Tell the class that you would like them to collect something that is easy to collect and count, such as bottle caps. Tell them that they are going to collect the item they have decided upon until they get one hundred of them. Decide with the class what they will collect. Then write what they have decided to collect in the space provided on the Letter to Family (PDF file) and send it home with each child.

Each day collect the bottle caps or other item you have decided to collect. When the children have collected ten or more, group ten together, put them in a plastic bag, and label the bag 10. Each day show the bags and the individual bottle caps. Ask, How many bottle caps do we have now?

Continue doing the activity until you have 100 bottle caps.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 4 on different ways to show numbers.


Doing the Investigation

Observe children as they are doing the activity. Those who group objects by tens show an understanding of place value. Suggest to those who are not grouping objects by ten, that grouping the objects by ten might help them keep track of the count.

When children are finished, have them talk about how they represented their number. The following are examples of what they might show for the number 28:

  • a picture of 2 groups of 10 objects, and 8 single objects
  • counters broken up into 2 groups of 10, and 8 single objects
  • 28 single counters
  • the number 28 on a calendar
  • the number 28 on a yardstick

Houghton Mifflin Math Grade 2