PI DAY
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Description: As the culmination of a unit on pi, Pi Day features measuring the circumference and diameter of
several objects and completing activities that encourage students to use the ideas of circumference, diameter
and problem-solving.
Learning Objectives:
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Students will understand the relationship between pi and the circumference of a circle.
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Students will learn teamwork and problem-solving.
Activity Time: 45 minutes
Materials:
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Hula hoops (four)
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Round fruit (oranges, grapefruit, cantaloupe, etc. — one piece of fruit for each student)
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Rulers (about 10)
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Open space (gymnasium, field, auditorium or cafeteria)
Directions:
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Have students discuss the circumference and diameter of the objects that will be used in the next
day’s activities to discover that the relationship between the two is consistently pi (the ratio of the
circumference of a circle to its diameter). Objects include the hula hoop and round fruit.
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Lead a class discussion on pi. Let students know that:
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Pi is always the same number, no matter which circle you use to compute it.
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The area of a circle is pi times the square of the length of the radius, or “pi r squared.”
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Pi is an infinite decimal; that is, pi has infinitely many numbers
to the right of the decimal point.
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Gather in an open space (gymnasium, field, auditorium or cafeteria)
and separate the class into four groups.
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The groups will be asked to complete these two activities:
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Hula twist – Have students hold hands in a circle with a hula hoop
looped around one student’s arm. The object of the challenge is to
move the hula hoop around the circle as fast as possible without
breaking the hand holds. Students may use whatever body
movement will help advance the hoop.
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PI DAY
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Fruit Pi – Have students select a round fruit, cut it open down the middle and use a ruler
to determine the circumference of the fruit by multiplying the diameter by pi. Allow students
to eat the fruit or take it home.
When the groups have completed the two activities, have them gather together and form one large circle.
Reinforce what they have learned about pi.
Submitted by Donna McCulloch, Buncombe Community School, Swannonoa, North Carolina
Correlation to National Curriculum Standards:
Understand numbers, ways of representing numbers, relationships among numbers, and number systems.
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Develop, analyze and explain methods for solving problems involving proportions, such as scaling and finding equivalent ratios.
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Work flexibly with fractions, decimals and percents to solve problems.
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Understand and use ratios and proportions to represent quantitative relationships.
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Use factors, multiples, prime factorization and relatively prime numbers to solve problems.
Understand meanings of operations and how they relate to one another.
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Understand the meaning and effects of arithmetic operations with fractions, decimals and integers.
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Use the associative and commutative properties of addition and multiplication and the distributive property of multiplication over
addition to simplify computations with integers,fractions and decimals.
Compute fluently and make reasonable estimates.
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Select appropriate methods and tools for computing with fractions and decimals from among mental computation, estimation,
calculators or computers, and paper and pencil, depending on the situation, and apply the selected methods.
NCTM http://standards.nctm.org/document/chapter6/numb.htm
The National Football League and the American Heart Association are proud to work together to produce What Moves U.
www.WHATMOVESU.com/teacher