Fickled Fractions

Elizabeth Chambers Keller Gifted Magnet Center
3020 W. 108th St.
Chicago IL 60655

Objective: (Grades 4-8)

To review the ways in which fractions are made real in our world
To show the relationship of cross multiplication and equivalent fractions
To reinforce fraction skills

Materials Needed:

Measuring tape Construction paper
Pencil Equivalent fraction strips
Crayons Ditto of a boy and girl doll

Recommended Strategy:

This lesson has been designed to enrich the students understanding of fractions
after they have completed the study of fractions. Now we will attempt to show
that fractions indeed have a place in the real world.
The students have learned to add, subtract, multiply, and divide fractions.
They also know how to:
-change mixed numbers to improper fractions.
-reduce fractions to lowest terms.
-change fractions to a decimal; to a percent; to a ratio.
-find the LCM and GCF.
-solve or make equivalent fractions.
The students will have a discussion about why fractions are so important and
why students find understanding fractions so difficult. How can we make
fractions real to them? Following the discussion, the students will do various
activities: -Label a doll that represents the students measurements.
(students will add, subtract, multiply, divide, and reduce
fractions using their body measurements.)
-Use a calendar in order to do an activity that is a lead-in
to cross multiplication and proportions.
-Play an equivalent fraction game to reinforce problem
solving techniques.

Performance Assessment:

Students will set up a proportion in order to solve word problems.

Multicultural Connections:

The proportion property was recognized by the early Hindus as an arithmetic
rule. In the Seventh Century it was called the rule of three and was stated in
words in the style of the times. Merchants regarded the rule highly and used it
widely as a mechanical procedure without explanation. Prior to the Nineteenth
Century the ability to use the rule of three was a mark of mathematical
literacy. This explains cross multiplication and also how to find an unknown in
solving proportions. Ex. a/b = c/d therefore aKd = bKc
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