Pumpkin Patch Math
Lesson 9 of 10
Objective: SWBAT choose and represent a strategy to represent take away problems.
Setting Up the Learning
We will open the lesson by doing a shared reading of "5 Little Pumpkins". This fun poem will get students engaged in taking away pumpkins, and aligns to RL.1.10, "With prompting and support, read prose and poetry of appropriate complexity for grade 1".
Here is the youtube version!
In our poem, we started with 5 pumpkins and we took away all 5! Today we are going to look closely at a take away problem to see what strategies we could use to solve this problem.
We have to think about how we can solve take away problems so we can solve them in our brains one day! We have lots of tools to help us. I want you to see if you can think of 2 ways to solve each problem, that makes your brain really understand how to do the problem.
Your thinking job today is: What strategies can I use to solve my take away problem?
I have a story problem here. Our job is to figure out are we putting two groups together (teacher models a put together hand motion) or taking away (teacher models hand motion)?
See video for hand motions and visuals.
Here is the first problem:
I have 10 pumpkins in my wagon.
I drop 2 of my pumpkins.
How many pumpkins do I have now?
Guiding Questions (These teach kids how to work through a problem, addressing MP1, make sense of problems and persevere in solving them):
- Let’s read it one more time because great mathematicians read problems 2 times.
- 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 pumpkins at the end?
- Partner Talk: So now we have to decide-did we put together or take away? How do you know for sure?
- Partner talk: How can you figure out this problem?
I’ll share out a few ideas to get kids thinking.
Common Core emphasizes that students should be able to understand and use a variety of strategies to solve addition and subtraction word problems. To that end, I am pushing students to show 2 ways to solve their subtraction word problem.
I'll say: “I’m challenging you to see if you can come up with 2 ways to solve. So maybe you will show fingers first, but I want you to think of another way to solve it!
Student Work Time and Share
While students work, I'll be floating to get a sense of what strategies they are using and push their thinking.
Possible Strategies to look for:
- Direct Modelers: Get out 10 cubes, take away 2; Put up 10 fingers, put down 2 (Most of the kids will be here)
- Counting Strategies: These students might use a number line (I’ll have them out for students to use if they want) or they might count backwards.
- Mental Math: These students may “just know” the answer. I’ll push these kids to explain exactly what they did in their brains. To help them with that, I’ll say, “What did you do first in your brain? Tell me what to do first”
See attached video of a student working!
I’ll choose 2 students’ strategies to share with the class. (One will definitely be a number line or counting strategy)
- What did they use to represent the pumpkins? How did they show that I dropped 2?
- How are these strategies the same? How are they different?
- How would this problem look on a number line? (Even if a child doesn’t use it, model what a child did with cubes on the number line)
- Why did we go backwards on the number line? Why didn’t we jump up to 11?
I am not having students write number sentences yet so we can just focus on what is happening in the problem. As a scaffold, I am just exposing them to the number sentence for now.
For exposure: “I’m going to write what happened in this problem in numbers: First we had 10 pumpkins (Write 10), then we dropped, or took away, 2 (write -2) and that was the same as having 8 (write =8)."
See attached picture of the anchor chart we created!
See attached document for all Group A-C work.
Goals for this group: Students get 3 problems 2 subtraction, 1 addition—I may give these students the put together/take away stickers from yesterday
Independent Practice: 3 problems, numbers under 7
Goals for this group: Students get 3 problems 2 subtraction, 1 addition; I want these students to show 2 strategies for the first problem.
Push: You showed this with fingers. Now could we think of a way to show it with numbers?
Independent Practice: 3 problems, numbers under 12
Goals for this group: Push this group on strategy type-are they using a counting strategy yet? If not, encourage them to think through it.
Prompting Question: Can you do this without fingers or cubes?
Independent Practice: 3 problems, numbers under 15
I'll choose 1 student to share out his/her strategy (preferably a strategy that I did not share earlier).
I’ll hang the chart paper in the classroom so students know where it is and can refer to that strategy later in math!