SWBAT will use a strategy to count and combine groups of 10. SWBAT engage in activities that will promote fluency with complements of 10.

Now You See, Now You Don't! Can you visualize 10? Today your students will let you know if they can or can't.

5 minutes

I start by asking the kids to stand in a circle on the carpet.

*"You are going to play a game of POP. You will start with the number 101 and you will count up until you get to the last number 120."*

This is a game that was introduced in a lesson at the beginning of September and has been played throughout the school year. To see a full description of this activity, please see the linked lesson.

I am choosing this number range because it is expected that first grade students can count up to 120. Students tend to get stuck on the 109 to 110 transition and I often will hear, "109, 200." The CCSS expect that 1st grade students can "count to 120, starting at any number less than 120 (CCSS.Math.Content.1.NBT.A.1)."

There is a video of the student splaying this game in the section resource.

20 minutes

I have the students gather as a group and face the large whiteboard in my room. On the whiteboard, I have a blank ten frame. I use a magnetic one but you could always just draw one in.

**I have used these ten frame cards throughout the year. If this is the 1st time you are using them, you will want to make sure that the students understand the the structure of a frame. This being that there are 5 boxes on top and 5 boxes on the bottom.*

**"I am going to flash a tens frame card at you. I want you to figure out how many dots are on the card. Once you know, I want you to put your thumb on your chin and not shout out your answer."**

I then flash the card and call on students to share how they figured out how many dots there were. There is a video, in the section resource, that models this introduction. The CCSS expect students to "communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning." (CCSS.Math.Practice.MP6) In this activity, I am trying to allow as many students as possible to be called on to articulate their thinking by saying how many dots they saw and how they saw it. Although I ask kids to put their thumb on their chin (once they have an answer), I call on any child. This is something that my students have come to expect. You will have to figure out a system that works for you and your students.

There are two videos that document how two students explained their thinking. You will see how I used the ten frame visual and an equation to support their thinking.

Through this activity, students are also working on developing fact fluency within 10 and the ability to add and subtract within 20 (CCSS.Math.Content.1.OA.C.6).

**Differentiation**: I have four students that are secure with their complements of ten and have been working with them on complements of 20 (through homework, Morning Meetings Activities, and math class). Instead of having them sit through this discussion of 10, I had them work in pairs with 20 frame cards. They are located in the section resource.

30 minutes

Students have a choice of activities during station time. They can start with any of them and need to play at least two of them before the station time is finished.

*Complements of 10*: This game was explained in a prior lesson. If you go to the link, you can read an explanation of the activity and find the resources that you need for the activity.

*Complements of 20*: This game was explained in a prior lesson. If you go to the link, you can read an explanation of the activity and find the resources that you need for the activity.

*Three Stacks*: This activity was introduced and played in a previous lesson. You should review the lesson and print off the materials needed. This game is also focusing on combinations of 10.

10 or 20 Frame Cards: These were introduced in the previous section. There is a video of students using ten frame cards in the section resource. I have added that I want students to say who many dots and how many more to ten (and the same for twenty). This way they are working on the complements too.

As students are working, you should circulate to see how students are doing with their complements of ten, if they are fluent with them, need more practice, and/or ready to move on to complements of 20. I used a simple checklist (see the section resource).

The 1st, 2nd, and 4th activity have the students "making sense of quantities and their relationships in problem situations (CCSS.Math.Practice.MP2)."

The CCSS expect students to look for and make use of structure. In this case I am hoping that students see that 2+8 is the same as 8+2. I am also expecting that students will see the connection between 10 and 20 complements (CCSS.Math.Practice.MP7).

10 minutes

I gather the students back together and go over the ten and twenty facts sheets. I give out the appropriate sheet to each student (based on students fluency with complements of ten). These sheets allow me to see who well students are doing with their facts, their understanding of the equal sign, and their ability to represent ten or twenty with addition and subtraction equations.

With the equation 10= 5+ ____. I will be looking to see if any students write 15. This is a common mistake that students make.