Lesson 3 of 7
Objective: SWBAT use the established story problem process of visualizing, retelling, and modeling when solving addition story problems. SWBAT add two quantities up to 20 using the counting all or counting on strategy.
Choose a start with and get to number from the 1-30 number cards (These were created in a previous lesson and you should have them ready when needed). I allow students to draw from the deck and then decide if we will count forward or backwards. If you feel your class is still struggling with the counting back concept, I would use one as the get to number and practice going back to 1. Here is the link for a lesson where I teach this routine.
Review the story problem routine with the students. I will use a blank piece of chart paper to create an anchor chart for the procedure. I will later display this in a spot that kids can refer to, when needing to use the process.
Remember the procedure is:
1. Visualize the story
2. Retell the story after you have heard it
3. Determine if the result will be more or less than the amount you started with.
4. Share strategy for solving problem (manipulatives can be used).
5. Model method for recording
*I want to model and practice this routine as frequently as possible. I want to establish that this is the norm for how we approach word problems.
It was Free Choice Time in the classroom. Ann and Andy were playing with Legos. Ann had 3 Lego people and Andy had 3 Lego people. How many Lego people did they have altogether?
It was still Free Choice Time. Ann and Andy were still playing with Legos but now Ann had 4 Lego people and Andy had 3 people. How many Lego People do they have altogether?
I will present these stories separately. Once they have discussed and shared their strategies for each, ask them if solving one of the problems can help solve the other problem. If no connection is made, make sure to point it out. Focus on if the problems look similar or not. Students are writing and equation and/or documenting their strategy that they used to solve the problem CCSS.Math.Practice.MP4. Students are using their knowledge from the first problem to help solve the second problem. The connection of using the 3+3 to solve 3+4 (as being one more) is an example of this CCSS.Math.Practice.MP7. Students are using drawings or equations to represent the action in the story problem CCSS.Math.Content.1.OA.A.1.
Diving Into A Story Problem
Advanced Preparation: Write the problem below on a piece of chart paper. You will use this to introduce the problem and the later on in the session Wrap Up.
I start by gathering all of the students in front of the whiteboard and read the following problem (reminding them to visualize the story).
I was cleaning up the art center. I found 5 crayons on the floor. I found 6 more crayons on the counter. How many crayons did I find altogether?
Reminding the students that they are not thinking about the answer yet, I ask a couple of students to tell me the story in their own words.
I then tell the students that they will go find a spot in the room to work on this problem by themselves. I remind them that they can use cubes, counters, fingers, etc. I also want them to know that they should keep track of how they solved the problem. They can use pictures, numbers, and/or words but there work needs to be clear enough that soemone else can look at it and tell how you solved it.
For students who finish quickly offer the following problem: I was cleaning the art center. I found 20 crayons. I found 11 on the floor and some more on the counter. How many were on the counter? This problem is much more complex and will offer a challenge to the students but also give you an idea about their ability to find differences and the approaches they use. This problem is introducing the idea of the missing addend. Students may use addition or subtraction to solve this problem. The students are using a procedure to solve the story problems. The idea that they visualize it and think about the action is the entry point into the problem.(CCSS.Math.Practice.MP1. Students are using numbers and equations to represent their thinking. CCSS.Math.Practice.MP4. The students are using addition within 20 to solve word problems involving situations of adding to. They are doing this by using objects, drawings, and equations. CCSS.Math.Content.1.OA.A.1).
NOTE: It is important that you observe how students are sharing and note students who use different approaches. I will encourage three students to share their work at the end of the lesson. You never want to have just one example used. This would promote the idea of the modeled approach being the only way of solving the problem.
Session Wrap Up
The focus of this part of the lesson is to see how students find the total of two quantities up to a total of 20. I will also continue to focus on the use of standard notation (with + & = signs) for representing addition situations.
I start by calling all of the students to gather back as a group (where ever your Focal Point is). I ask several students to share how he/she solved the problem (I choose students from the observations I made during the work time). As students are sharing, record each strategy on the chart paper (crated earlier in the lesson). After two or three have shared, ask the students if anyone else has a different way of solving this problem?" I will also add addition equations as each strategy is shared. I will make sure and review the symbols used in the equation. The students are sharing out their strategies and explaining how they approached the problem. In return, the other students are connecting their strategies to one that was modeled CCSS.Math.Practice.MP6.
Once I have three or four approaches on the chart paper, I ask the students to identify which approach was closest to the way he/she solved it.
The students are sharing out their strategies and explaining how they approached the problem. In return, the other students are connecting their strategies to one that was modeled. I am looking for strategies such as counting all, counting on, or using a known fact.