Is Your Dance Card Full?
Lesson 8 of 10
Objective: SWBAT distinguish between joining and separating problems.
I have 2 story problems here. Our job is to figure out if the problem is a put together or take away problem.
I'll practice the hand motion with students and show them the put together/take away stickers. When we read the problems, we will label it as put together/take away by placing one of the stickers on the problem. (See video of these hand motions, along with the visuals used for "the stickers").
Here is the first problem. We will chorally read it twice.
At the Jungle Dance, there are 7 animals dancing. Gerald leaves. How many animals are dancing now?
Guiding Questions: These questions push kids to understand how to work through solving a problem. This specifically hits on CC Mathematical Practice 1: Make sense of problems and persevere in solving them.
- Let’s think about what happened in this problem. Who can tell me the story again?
- Now think about the story in your brain. Were there more or less animals at the end?
Partner Talk: So now we have to decide-did we put groups of animals together or did we take away animals? (I'll push students to use evidence from the problem to explain why.)
We will act out the problem with our bodies to make sure we are right! I’ll have 7 students be the animals dancing on the rug, then 1 will leave. Did we get more or did we take away some?
For exposure to the minus sign, I’ll say: First there were 7 animals (I’ll write 7), then 1 left (I’ll right -1) and that is the same as having 6 (write =6)
During this part of the lesson, we will follow the same routine as the opening discussion, but we will do more student partner talk.
Present problem: There are 3 animals on the dance floor. 5 more animals come to dance. How many animals are dancing?
Partner talk questions:
- Retell what happened at the Jungle Dance! (I’ll choose one child to retell the story.)
- Now think about the story in your brain: Were there more or less animals dancing at the end? How are you sure?
- Now I need to figure out if this problem goes with the other problem or goes on the put together side. Did we put two groups of animals together or did we take some away? (I'll choose one rationale to share out with the team).
We will act out this story with our bodies on the carpet, as we did before, verifying that we did have more animals dancing at the end of the problem.
For exposure to the addition symbol, I'll write the number sentence: "Now watch how I write it in numbers. First I had 3 (write 3), then 5 more came (I’ll write +5) and that is the same as having 8 (write =8)."
Students will receive put together/take away stickers. I just print these on 2" x 4"mailing labels and they instantly become "cool" stickers! Oh first grade. Students use these to label the problem before they solve it.
All students solve 3 story problems, complete with strategy, answer, and words to explain their thinking. The CCSS emphasize writing across the curriculum, so students should write at least 2 sentences explaining what they did to solve.
Group A: Numbers under 8
Group B: Numbers under 12 (see attached picture-Strategy Group B- for example student work!)
Group C: Numbers under 15 (see attached Strategy C pictures for example student work!)
I'll push this group to solve the problem without the support of cubes or fingers to encourage counting strategies.
See attached problems and "stickers"!
Today we figured out if problems were put together or take away.
I'll select 2 students to quickly share out how they solved their first problem. I'll hopefully get to share a cubes strategy and a counting strategy (counting backwards, number line, etc).