TITLE:ÊÊLEARNING ABOUT RATIOS: A SANDWICH STUDY
AUTHOR:Sheryl Weinberg; Southeast Island School District, Ketchikan, AK
GRADE LEVEL/SUBJECT:4-6
OVERVIEW:Ratios can be a difficult idea for elementary students to grasp.
Spending time manipulating "real" objects provides a tangible reference
when later dealing with the concept .. in either an abstract or practical
fashion.
PURPOSE:The purpose of this activity is to provide students with a concrete
introduction to the concept of ratios.
OBJECTIVES:As a result of the activity, 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.
RESOURCES/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
sample graph:Peanut Butter and Jelly Study
Peanut Butter Jelly Rating
5 T 0 T 1 2 3 4 5 6
4 T 1 T 1 2 3 4 5 6
3 T 2 T 1 2 3 4 5 6
2 T 3 T 1 2 3 4 5 6
1 T 4 T 1 2 3 4 5 6
0 T 5 T 1 2 3 4 5 6
ACTIVITIES AND PROCEDURES:
1. 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. List student comments on the board.
2. Randomly select 10 students to come forward. Divide the pupils into
groups by sex. Have seated learners count the number of boys and girls.
Write the numbers above each group, separated by a colon. Explain that
this expression identifies the ratio of boys to girls called forward.
Physically structure two additional examples (ex: students by hair color,
lunch to milk tickets, pupils that write with pens to those that use
pencils.) Label examples. Return to the term on the board and student
comments. Have students identify which, if any, ideas identified what a
ratio is. Guide pupils in defining the term.
2. Divide class into groups. Direct each group to make a series of six
peanut butter and jelly sandwiches, each containing a different ratio of
the given spreads. Pupils are to label each ratio. Cut each sandwich
into pieces.
3. Conduct a taste test of the preferred ratio. Have each student within
the group taste each sandwich and rate it on a scale of one to six.
4. Direct pupils to graph and report the results of the trial individually,
and then for the group.
5. Have each group share their charts with the rest of the class. Compare
and contrast differences.
TYING IT ALL TOGETHER:
1. 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.
2. Have students divide themselves into triads or quartets. Explain that
each group is expected to 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. Indicate which day students should be prepared to conduct and
present their tests.
Click here to return to OFCN's Academy Curricular Exchange
Click here to return to OFCN's Academy
Click here to return to OFCN's Main Menu
John Kurilecjmk@ofcn.org