SWBAT identify missing numbers on a 100 grid using patterns and sequencing of numbers.

Why is 7 the most vicious number? Because 7 ate 9! Sequencing numbers is one strategy that students will use to identify missing numbers from 1-100 and explain how they knew what was missing.

5 minutes

I will gather the kids on the carpet for a few rounds of Start At/Stop At. I changed the numbers for this activity a few lessons ago. For a complete breakdown of this activity and the number cards needed to play, please see the warm up section of the linked lesson.

20 minutes

Advanced preparation: You wil need a 100 grid that you can remove numbers from or cover numbers with a tile or stick it note. I have included a 100 grid in the section resource.

** "Please come and sit in front of the 100 grid that I have hanging on the easel. Today we are going to use this Number Grid to play a game called What's Missing. I will ask you to shut your eyes and then I will remove 5 cards from the number grid. I will then ask you to open your eyes and try to figure out what numbers are missing. I will also ask you why you think it's that number (their answer)."** There is a video in this section's resource that has a student explaining how she figured out what number was missing.

It is expected that mathematically proficient students "justify their conclusions, communicate them to others, and respond to the arguments of others (**CCSS.Math.Practice.MP3**)." In this case, the students are using the structure of the number grid to defend their answers.

I then call on a student to offer their answer. After they explain their answer and how they figured it out, I ask others to raise their hand if they used that strategy and if anyone found the number in a different way. The expectation is that mathematically proficient students "look closely to discern a pattern or structure (**CCSS.Math.Practice.MP7**)." In this case, students are using the structure of the rote sequence, or of the tens and ones columns, to defend their thinking.

I continue this for the rest of the numbers.

*"We will now play another round, except this time I will add this recording sheet."*

I show them the sheet from the resource section titled, What's Missing Game. I then ask for a volunteer to play the game with me. I have the volunteer be the player that hides 5 numbers. Once the numbers are hidden, I use the document camera to demonstrate how to fill it out.

**"I will look at each missing number and then record what I think each one is using the lines on the paper. Then my partner and I will check the answers and I will fix any mistakes. Then we will switch roles and my partner will fill out his/her answers of the second line of Game 1 (see recording sheet)."**

Note: It is sometimes hard for first graders too remember how to write teen numbers. This is a good chance to talk about that and, if it comes up, to discuss who easy to confuse two numbers with the same digits in different order, such as 15 and 51.

30 minutes

There are three center time choices today. I will require that each student plays the What's Missing Activity and then they can move on and choose from the other two or play a second round of What's Missing.

1. What's Missing: Students should work in teams of two to play this game. It was explained in the a previous lesson. Each group will need a 100 grid, a recording sheet, and something that will cover 5 different numbers on the number grid (it depends on the size of the grid you are using). I have included a video and picture of the game being played.

2. Oral Counting on the Classroom Number Line: Students can practice ether oral counts using the classroom number line. Students can count by themselves or partner up and switch every other number.

3. Number Tapes: A description of this activity can be found at this link. ." All three of these activities are working on some facet of this goal.

10 minutes

I ask the students to rejoin me in front of the easel and had ether face the new number grid that I have hung up. This new grid is from 101-199. I then play a new round of What's Missing using the higher numbers. I have attached a quick video of the game we played.

5 minutes

I end the session with the students filling out the number grid fill. You will need to make a copy for each person. I will use this as a formative assessment piece, to see who students are doing with writing their numbers, in sequence, from 1-100.