The purpose of this activity is for students to organize and count a collection of 40 objects. They are introduced to Stage 2 of the Counting Collections center. Students should have access to double 10-frames, cups, paper plates, or other tools that may help them organize as they count. Students can organize, count, and represent their collection in any way that makes sense to them.

Monitor for and select students with the following approaches to share in the Activity Synthesis:

• Organize the collection one by one, count each object one at a time.
• Organize the collection into groups of ten, count each object one at a time.
• Organize the collection into groups of ten, count each group by tens.

The approaches are sequenced from more concrete to more abstract to help students use what they know about tens to organize and count collections of objects. Aim to elicit both key mathematical ideas and a variety of student voices, especially from students who haven’t shared recently.

Students count a collection of 40 objects during this activity. The collections include quantities up to 99 when Stage 2 of the Counting Collections center is offered as a choice in later lessons.

• Invite previously selected students to share in the given order. Record or display their work for all to see.
• If students only share how they organized and counted, represent each approach with a labeled drawing for all to see.
• Connect students’ approaches to the learning goal by asking:
  • “How are the ways they organized their collections alike? How are they different?” (They organized all the objects in their collection to make them easier to count. The first way didn’t use any tools to organize their collection. The other ways used tools by putting 10 objects in each tool.)
  • “How are the ways they counted their collections alike? How are they different?” (The first two students counted their collections by ones. The last student counted their collection by tens.)

The purpose of this activity is for students to practice counting and representing collections with multiples of 10 objects. Students count one bag with their partner. When students have finished counting and recording, they switch bags with a different group. Then they count a new collection. During the Activity Synthesis, students discuss using a tool that organizes the objects in groups of ten, and how this is helpful when counting a collection.

Bags B–D will be used again in a future lesson in this unit.

• Invite previously identified students to share.
• “How did they use tools to help them count?” (You don’t need to count every object when you use a tool. You can use a 10-frame to organize 10 objects. Then count how many tens there are.)
• “Today we saw and used different ways to organize and count collections.”
• “Ask your partner, what is a new way you organized or counted your collection? Why did you choose to use this new way?” (I tried counting by tens because I saw this way being used in the last activity. I tried organizing my collection using a 10-frame because I can just count by ten.)