Working with the Intervention Group
In planning the first intervention lesson, I wanted the students to see the num-
ber 9 and its parts by using linking cubes. I knew they needed experience with
concrete models and in verbalizing what they were doing before they could begin
to see patterns and make conjectures about how addition and subtraction work.
My plan was for each student to build a train of 9 with the cubes, and then break
that 9 apart into 2 groups. I would record the combinations on a small whiteboard
and watch the children carefully as they worked.
Although the plan seemed simple and direct enough to me, I was surprised by
the children’s responses. I began by telling them that we would be reviewing the
number 9 using cubes. I asked them to use the linking cubes to build a train of 9
cubes. As they were working on this task, I noticed that Mia had 10 cubes, so I
asked everyone to count their cubes again. Keith Allen was taking a long time
looking for specific colors so that he could make a pattern, so I had to tell him not
to worry about the colors. When everyone finished their cube train, I asked the
children to break the train into 2 parts. The children seemed confused, so I mod-
eled with my own train of 9 cubes. When I saw that each child had broken their
train into parts, I said, “Tell me how many you have in each part. I see you broke
the 9 into different numbers of cubes.”
Mia was the first to volunteer. While we all watched, she said, “Two,” as she
pointed to 1 group of cubes, and then counted the other group, “1, 2, 3, 4, 5, 6, 7.”
I wrote 2 7 on the whiteboard and asked her, “How many is that?” Mia then
started with the group of 2 and counted all the rest of the cubes by 1s to answer
- Kelvin was the next to share. He had broken his cubes into 3 and 6. When
asked the total, he too began counting the cubes from 1.
Connor then shared that 9 3 9. I knew that he was confused, so I tried
using a context to help him realize that you can’t subtract something and end
up with the starting number. I asked the group, “If I had 9 pieces of gum and
gave 3 pieces to my friends, how many would be left?” Nicole used her train of
9 cubes, took away 3, and yelled out, “6.” Even though the task was to make 9,
not subtract from it, I felt it was important for the group to visualize this prob-
lem in a real-life context. We then continued for a few more minutes using
cubes to find combinations of 9—sometimes connecting the numbers to sto-
ries.
After giving this small group additional practice, I wanted to bring the ideas
we worked on to the whole group, both as a review for the whole class and to
assess if and how the intervention group students would be able to contribute to
the whole-class discussion. I prepared the intervention group by telling them that
after recess we would review the number 9 with the whole class. I ended the ses-
BUILDINGUNDERSTANDINGTHROUGHTALK