SWBAT count groups of tens and ones. SWBAT add 10 and subtract ten from a given number.

This task will offer a challenging activity and will also act as a piece of formative assessment as you look deeper into how well they can add or subtract ten from a number and plan your instruction from here.

10 minutes

Explain to the students that they are going to play another round of Popcorn. Remember, it is a counting game where you start with a number (pre-determined) and you count up until you get to the last number (pre-determined). Ask them to stand up in a circle. Tell the students that they are each a kernel of popcorn and ask them what happens when you heat up a kernel of popcorn? That's right, it POPS! Explain that today we will count back. We will start with the number 93 and count to 3. I will say 93 first. Then the person next to me will say 83, and then the next person 73 . . . until 13. After 13, you say 3, say POP and then sit down. The game will continue with the very next person starting the count all over again. The game continues until there is only one person left standing. That person finishes the game by repeating the entire count sequence. In this activity students are mentally adding or subtracting a ten from a number (CCSS.MATH.CONTENT.1.NBT.C.5).

If time permits, I will then play one more round but having the students start at 5 and count off the decade by 10s.

I will also introduce a 100 bead tool that will allow the students to create a visual of counting off the decade by ten.

There are two videos of this section of the lesson in the section resource. The first video is an introduction to the tool, and the second demonstrates starting at 5 and counting by 10s.

Note: Some students may still need to use a number grid or lien to help them with this activity.

30 minutes

Advanced Preparation: Make enough copies of the Mid Unit Check In for your class.

*"Today, I am going to ask you to start by choosing a station activity. The choices are all activities that we have played during this unit. As you are playing, I will call you over and solve a few problems for me. The problems are all focused on counting by 10s. Once you are finished with the task, you will be able to return to your station activity. If you finish one activity, you can choose another one."*

By having the students start with station activities, I can manage the assessment task in a way that will allow me to see specific students take the task on 1:1 basis. Based on student work/ performance, I want to specifically watch a few students work on this task. This way I can see how they are solving each part. I want to make sure that they are counting by 10's and 1's and/or just adjusting the tens digit by 1. For the students that I know are secure, I can call them over a few at a time because I am confident of their ability to efficiently solve these problems.

I have included a video of a student, who met the standard when completing the task. I have also included a video of a of a student who demonstrated the ability to count by 10s, switch to counting by 1 and then switched back to counting by 10s. This ability is a higher level than counting all of the tens and then the ones.

In the resource section is a copy of my notes on the students that I observed take the assessment. As you can see, my notes allow me to know how each student solved each task. These notes are useful when I look at their recording sheet. They allow me to have a qualitative, more complete understanding of their thinking.

This assessment task has the students adding within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10 by using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship (CCSS.MATH.CONTENT.1.NBT.C.4).

The students are also given a two-digit number and are mentally finding 10 more or 10 less than the number, without having to count. They are also able to explain the reasoning used (CCSS.MATH.CONTENT.1.NBT.C.5 and MP3).

Students are also subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 using concrete models. They are relating the strategy to a written method and explaining the reasoning they used (CCSS.MATH.CONTENT.1.NBT.C.6).

40 minutes

Students who are not working on the assessment task can choose from any of the station captivities listed below. Each station has been introduced and played in a previous lesson (in this unit). For a detailed description and the resources need for each activity, click on the link associated with each choice.

- Roll A Number: This activity can be found in the introduction section of the linked lesson.
- Drop Sticks: This activity is found in the station time section of the linked lesson.
- 100 Grid Challenge: This activity can be found in the introduction of 100 Grid Challenge section of the linked lesson.

5 minutes

I will ask the students to meet me on the carpet and hand out their sheet for today's Mad Minute exercise. This routine was introduced in a previous lesson. Please check out the link to get a full overview of this routine.

I want to really focus on fact fluency and build upon the students ability to solve within ten fluently (CCSS.MATH.CONTENT.1.OA.C.6). I am going to use the Mad Minute Routine. This is a very "old school" routine, but I truly feel students need practice in performing task for fluency in a timed fashion. Students need to obtain fact fluency in order to have success with multiplicative reasoning. Students who don't gain this addition fact fluency by the end of 2nd grade tend to struggle with the multiplicative reasoning in third. Having this fluency also allows them to work on more complex tasks because the have the fact recall to focus on the higher level concepts.