# Students as Teachers Part II

## Objective

SWBAT explain the processes they use to solve math problems.

#### Big Idea

Students are given the chance to teach about how they solve math problems.

## Filming and Working

30 minutes

In day 2 of this lesson, students will present their methods for working with place value. On Day 1 they worked on how to solve problems, and now they will explain their thinking on camera.

While the students are being filmed, I place them in 3 ability based groups, as a result of a previous assessment. One group is working on place value with Hundreds, Tens and Ones. One group is working on addition with double digit numbers using base ten drawings. The third group is working on double digit subtraction. I have prepared a practice sheet for each groupword problems for film lesson.pdf. My goal for students is to strengthen their understanding of 3 digit numbers (2NBT.A.1), and to use that understanding to solve word problems ( 2OA.A.1) -for those who have demonstrated mastery of understanding that a 3 digit number is made up of hundreds, tens and ones.

I begin with a discussion of how we have so many math tools in the room, but we do not always have them with us. Sometimes we only have a paper and a pencil. How can we transfer our tools to paper and pencil. I let students suggest their ideas. We make a list and then I help them to notice that many of the tools we can draw on our paper, such as base 10 blocks, a part of a number grid or number line, etc.  I am hoping that students will develop the ability to model with mathematical representations (MP4) of the tools that they are most comfortable using to solve math problems.

I tell them that I will draw base ten blocks today as my tool. I draw a large square and ask them which block this represents (100); I draw a straight line (10) and a small dot (1). I put up a 3-digit number and ask them which block I would draw where. I follow their directions. I try to be very careful to attend to making my hundreds, tens and ones clearly differently by attending to the precision of my drawings (MP6).  I tell them that today when they are looking at numbers, or adding, or subtracting, I would like them to draw the base ten blocks. I tell them that even if they can do the work in their heads, they can use the base ten block drawings to check their thinking. If they can begin to draw the blocks when they need help figuring out a problem, it is one structure that they can always have available for solving problems (MP7), even when they don't have the actual blocks. Students are making the transition from manipulatives to representations of those manipulatives as they work today.

As students are working on the problems, I call up one group at a time to film their explanations of place value and place value addition and subtraction. Because I am filming the groups, students help one another and hand in their papers for me to check later.

## Closing

10 minutes

I bring students to the rug for a closing game of Tic Tac Toe. I draw a board with 9 squares. I label the squares a,b,c,d,e,f,g,h,i. I divide the students into 2 teams. Each student has a chance to answer the question individually. I remind students that we do not cheer or boo people for right or wrong answers. It is a game and we need to show respect for everyone in the class. I do provide scaffolding for those who may be struggling by possibly reading the number out loud and stressing the place for them, or pointing to the individual blocks and asking how many hundreds, tens, ones.. and recording for the student to see the number as a whole.

On the squares I write 3 digit or 4 digit numbers and underline 1 digit, or I write numbers in base 10 block notation. I tell students that 1 person from the team will pick a letter and tell what the value is, or what number is in the block. If they get it right I put an X or O on the square and then play moves to the other team. We continue until there are no squares left.

I need to upload all of the videos for viewing at another point so we do not watch them today.