Braga Kim & Michelle Verre CLE M/s/t: Fractions Lesson Title: Inch by Inch Source: http://illuminations.nctm.org/LessonDetail.aspx?ID=L545 Curricular Connections: Math Materials: standard ruler for each student and activity sheet, also a blown up ruler for the board. Grade Range: 3-4 Lesson Overview: Students will use rulers to represent various fractions as lengths. Students will use a ruler to measure a variety of items, including items which can be measured to the nearest half and quarter of an inch. M/S/T Standards and Evidence Students Will: (3.N.10) develop an understanding of fractions as part of a whole unit and as parts of a collection. Evidence: Students will be developing an understanding of how inches are a fraction of a foot, and inches have fractional parts that make up one whole inch. (3.N.11) use manipulatives, visual models, and illustrations to name and represent unit fractions (1/2, 1/3, 1/4, 1/5, 1/6, and 1/10) as part of a whole or a set of objects. Evidence: The students will be using rulers as a visual model and their activity sheet will have illustrations to represent fractions. (3.N.13) recognize fractional numbers as equal parts of a whole. Evidence: Students will be learning fractional parts of an inch, inch and a inch. (3.N.15) compare and order unit fractions (, , ) and find their approximate locations on a number line. Evidence: Students will be able to find these fractions of an inch on a ruler. (3.M.1) select tools and units (customary) appropriate for the length measured. Evidence: Students will be using rulers. (3.M.2) use a ruler/yardstick to measure to the nearest standard unit (whole and inches, whole feet, and whole yards). Evidence: Students will be using standard 12 inch rulers to measure to the nearest whole and half inches. (4.N.7) develop an understanding of fractions as locations on number lines and as divisions of whole numbers. Evidence: Students will be developing an understanding of fractions by using a ruler, also they will understand that an inch is a fraction of a foot, and inches have fractions of themselves ( and inch).
(4.N.9) use concrete materials and visual models to compare and order unit fractions or fractions with the same denominator (with and without the use of a number line). Evidence: Students will be using rulers, which is a concrete material that will help them grasp the concept of fractions. (4.M.2) use a ruler to measure to the nearest standard unit (whole, and inches, whole feet, whole yards, whole centimeters, and whole meters). Evidence: This is seen in the entire lesson, students will be measuring to the nearest and inch to realize that there are fractional parts of one inch and an inch is a fraction of a foot. Objectives: Students will: describe part of a linear region (ruler) using fractions. measure lengths to the nearest and of an inch using a standard ruler. demonstrate understanding that a fraction can be represented as part of a linear region. Prior Knowledge: Children have knowledge of fractions and fractional representations and a basic knowledge of fraction equivalences. Launch: The students will sit on the carpet in front of the white board. I will ask the students "What can you tell me about fractions?" This will refresh their knowledge of fractions for this lesson and I will write their suggestions on the white board and it will stay up there for the remainder of the lesson. Then I will tell the students that they will be measuring today with a 12 inch ruler. I will ask the class "Before there were rulers, how did people measure things?" The students will probably respond by saying that people used to measure things with their feet and hands. Then I will ask "Why can't we use hands and feet as a standard measurement?" a As class we will come to the conclusion that we can't measure with feet and hands because everyone has different sized hands and feet. Today one foot means 12 inches, and we will be using that today as a reference, 12 inch rulers. Then I will briefly go over the parts of the rulers. The ruler is 12 inches long, the inch mark is the line above the number, and the lines after are divisions of the inch which can be represented as fractions. A half-inch is the line between the numbers; it's a little shorter than the whole inch line. Then there are quarter-inch marks, which are shorter than the half-inch marks, and lay a little before and a little after the half-inch mark. As I'm saying this I will be holding a ruler and instructing the students to point out the marks. Also I will remind them that you always measure from the left side of the ruler. We will then determine the fractional value of each marking on the ruler, up to 1/16. Explore: First I will have all the students at their desk face the board and direct their eyes to the giant ruler (oversized on the board for the whole class to see). I will take a marker and make a dot where I want the class to measure to. I will call on some students and let them answer; I will do a few of these until it seems they have grasped the concept enough to do a worksheet on their own. Then I will pair the students off to work on a worksheet that deals with measuring. As they are working together I will go around and ask them
questions such as: "Which do you think is longer or inch? Show me where they are on the ruler. Which do you think it longer or inch? Can you show me where that is? Now how many inches are on a ruler? Which do you think is longer 7/16 inch or inch? Why?" The students will finish up their worksheets and find another pair to join and they will check their answers, if they are the same they will be done, or else they will have to talk it out with the group to decide which the correct answers are. This will be the time where I go listen in on their reasoning behind what they are doing to see if they are grasping the concept of the lesson. After this as a class we will report our answers and see if the class is in agreement. The next part of this explore phase is that I will have items listed on the board such as: the teacher's shoe, your desktop, a paperclip, an unsharpened pencil, glue stick, math book, crayon, length of the class window and length of a tissue box. Each pair of students will go up and put down their predictions in inches on the board with their initials next to it. After everyone has gone, each pair will take their recording sheet and actually measure all the items that are listed on the board. All the students will then go back and sit in their assigned seats. Summarize: The students will all be at their desks and have their results after measuring all the items and each pairs predictions are on the board. I will ask the class "Who can tell me, in inches, how long my shoe is?" I will call on a student and ask if the class agrees, and then write the exact measurement next to the predictions on the board. I will then circle the pair of names that had the closest prediction to the actual measurement. I will continue to do this with every item on the list. The students who were the closest to the actual measurements will win a reward from the prize box. Then we will go back to the white board and revisit where we wrote everything we know about fractions and relate it to our lesson today. How something can be measure as 1 and 1/4 th inch, or 2 and a half inches. Now they will know that fractions are also represented in measurement on rulers. That inches are broken down into fractional parts, and how inches are a fraction of a foot.