Kyle Razak & Troy Rall

Mathematics and Science Methods

Microteach: Percent, Ratio, Proportion, and Rate

11-23-1998

I. TEACHER INFORMATION

Title of Lesson: Learning about Ratios: A Sandwich Study

Topic(s): Math process: problem solving

Math product: measuring

Science process: constructing models

Science product: relationship between ratio of peanut butter and jelly to taste.

Student Level: 6th Grade

Objective:

A. Academic: Students will be able to:

1. Orally define ratio.

2. Demonstrate the ability to create ratios with given substances.

3. Label ratios.

4. Generalize the concept creating a ratio with a self selected material.

B. Social: Students will create a t chart showing what cooperation sounds and looks like.

Materials: chalk, peanut butter and jelly (one container per group), measuring spoons or cups, butter knives, paper towels, damp sponges, teacher developed graphs, pencils and paper for students

Prerequisite skills: graphing skills, averaging and rounding

Time Required: 25 minutes

Group Size: 6 students

II. TEACHING PROCEDURES

Introduction of Topic: Prior to class beginning, write RATIO in large letters in the center of the chalkboard. State objectives of lesson. Ask students to tell what they think the term means.

Development of the Concept: Have the students hold up what they are writing with. Count the number of pencils and the number of pens. Write the number of pencils and the number of pens on the board, separating them by a colon. Explain that this expression identifies the ratio of pencils to pens. Do the same for girls to boys.

Positive Interdependence: Divide class into groups of six. Direct each group to make a series of six peanut butter and jelly s sandwiches, each containing a different ratio of the given spreads. Pupils are to label each ratio. Cut each sandwich into 6 pieces.

Individual Accountability: Each student in the group will create one sandwich using the assigned ratio, which will then be shared with the rest of the group.

Criteria for Success: The students will then conduct a taste test of the preferred ratio. Each student within the group will taste each sandwich and rate it on a scale of one to six. The students will then average the rating for each sandwich and plot it on a graph.

Expected Behaviors: Students must successfully complete each job responsibility they are assigned in a cooperative fashion.

Monitoring: Move around the room making sure each group is working cooperatively and following the criteria established by the students for the t chart.

Processing: Each student will complete the cooperative group assessment form.

Conclusion: Each group will have one person report the group findings to the rest of the class. The results for the six groups will then be averaged and plotted on a graph on the overhead.

Evaluation: Students have completed the assigned tasks, and accurately averaged and plotted their rating on a graph.

III. EXTENSIONS:

Direct students to write what they learned about ratios. Ask them to verbally share what they wrote. Encourage students to describe any ratios that they are familiar with.

Have each group identify substances for a ratio study similar to the one conducted with peanut butter and jelly (ex: lemons to sugar to water, red to white paint to create the most desirable shade of pink...) Groups should develop a material list, method of study, and format for presentation of results.

IV. RESOURCES: Classroom textbook