## Inch Around This

### Mary Ann TaylorBay District Schools

#### Description

Students learn the concept of perimeter by measuring the perimeter of different shapes and creating shapes to be measured for perimeter.

#### Objectives

The student uses concrete and graphic models to develop procedures for solving problems related to measurement including length, weight, time, temperature, perimeter, area, volume, and angles.

#### Materials

-Enough 1-inch tiles for partners to share 5
-Enough 1-inch graph paper for each student to have two pieces
-Enough index cards for each student to have one
-Pencils
-Chalkboard and chalk
-Assessment worksheet for each student (See Preparations)

#### Preparations

1. Teacher makes an assessment worksheet for students. Draw at least 5 different figures on 1-inch graph paper. Duplicate enough copies for your class.
2. Put 5 tiles into a baggy. Have enough baggies so that each group of two students has one.
3. Have enough graph paper, index cards, pencils, and rulers for students.

#### Procedures

1. Put your students in groups of two.

2. Go over rules for working with a partner. For example: Be a good listener, take turns, pay attention, speak quietly, follow directions, etc.

3. Give each group 5 1-inch tiles. If the students do not have their own rulers, supply these too. Have each student measure the distance (length) of one side of one tile. Do this for all four sides of one tile.

4. Ask the students what the distance around the tile was. Say, “We call the distance around the sides of a flat geometric figure its perimeter.” Write this on the chalkboard.

5. Tell the students to put two of the tiles together. Have them measure the perimeter around two tiles. Have volunteers tell how they put their two tiles together and what the perimeter was.

6. Now tell them to work in pairs to put three tiles together and measure its perimeter. Have different volunteers go up to the chalkboard to draw the way they put their tiles together and to write the perimeter for those tiles underneath it. Students should come up with several different ways to place the three tiles together. Ask if the perimeter is the same regardless of the way the three tiles are placed.

7. Repeat #6 using 4 tiles and then using 5 tiles. Students should discover that placement of the tiles does make a difference on what the perimeter of the tiles will be.

8. Give each student one piece of 1-inch graph paper, an index card, and a pencil.

9. Tell the students they are to think of each square as a tile and outline some with a marker to make a geometric figure like they did with the tiles. They can use from 1 – 10 tiles in each shape. However, they must make at least 4 different figures. They can use the front and back of their paper and they need to number each figure. Then they need to measure and write the perimeter for each figure on their index card.

10. After both partners have finished their own figures and answers, they are to exchange graph paper and determine the perimeter of their partner's figures. They will write their answers on the blank side of their partner's index card. After they have completed this, they can turn their index cards over to see if they got the right answers! If there are any disputes as to what the correct perimeter of a figure is, the teacher needs to check it for them.

11. Take up graph papers, index cards, and tiles. Pass out another piece of graph paper that already has 5 figures on it. (This is something you need to make in advance and run copies of.)

12. Have the students write the correct perimeter for each figure. Take up the papers and correct.

#### Assessments

Students who correctly answer 80% on the assessment worksheet (See Preparations) will have shown adequate knowledge of this skill. Offer feedback and time to practice, then allow students to redo their worksheets.

#### Extensions

You could use centimeters instead of inches.