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Subject Matter:
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Mathematics - Algebraic Understanding,
Patterns
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Grade Levels:
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7-8
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Time Allotment:
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1-2 hours
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Overview
The Fibonacci series is a very dynamic application of mathematical
patterns in the real world. Fibonacci numbers can be found in many
aspects of nature - the number of petals on a flower is almost always
a Fibonacci number, the number of scales that make a spiral on a
pinecone or pineapple are Fibonacci numbers, and the proportions
of rectangles that create a spiral in a snail shell are Fibonacci
numbers.
Fibonacci was a 13th-century Italian mathematician. He is credited
with introducing the decimal number system to Europe and with discovering
a pattern that seems to occur over and over in nature in various
ways. The pattern was named after him - the Fibonacci series. The
series itself is fairly simple, but its applications in math and
nature can become quite complicated.
The Fibonacci Series:
The series begins with 0 and 1. After that, use the simple rule
Add the last two numbers to get the next. 1, 2, 3, 5,
8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987 ...
You might ask where this came from? In Fibonacci's day, mathematical
competitions and challenges were common. In 1225, Fibonacci took
part in a tournament at Pisa ordered by the emperor himself, Frederick
II. It was in just this type of competition that the following problem
arose:
Beginning with a single pair of rabbits, if every month each productive
pair bears a new pair, which becomes productive when they are 1
month old, how many rabbits will there be after n months? (http://plus.maths.org/issue3/fibonacci/)
Learning Objectives
Fibonacci numbers can be quite complicated and branch into many
areas of nature, art and mathematics. This lesson focuses on having
students recognize the origin of the Fibonacci series and its relationship
to the spiral shape.
Students will be able to:
- Analyze the number patterns found within the Fibonacci series.
- Comprehend the application of the Fibonacci series in several
real-world situations.
Oregon Standards available at:
http://www.ode.state.or.us/cifs
Mathematics - Algebraic Relationships
- Represent relationships among variables using words, tables,
graphs, patterns, generalizations and equations.
- Analyze relationships to explain how a change in one quantity
results in a change in another.
- Recognize, create, describe and analyze patterns and sequences
(arithmetic and geometric).
National Standards From the National Council of Teachers of Mathematics
(http://www.nctm.org)
In grades 5-8, the mathematics curriculum should include explorations
of patterns and functions so that students can:
- Describe, extend, analyze and create a wide variety of patterns.
- Describe and represent relationships with tables, graphs and
rules.
- Use patterns and functions to represent and solve problems.
In grades 5-8, the mathematics curriculum should include explorations
of algebraic concepts and processes so that students can:
- Represent situations and number patterns with tables, graphs,
verbal rules and equations and explore the interrelationships
of these representations.
- Analyze tables and graphs to identify properties and relationships.
- Apply algebraic methods to solve a variety of real-world and
mathematical problems.
Media Components
Video
Check the link at http://www.opb.org/edmedia/trs/
to find access to the video(s) from unitedstreaming™ referenced
in this lesson plan.
- "Mathematical Eye: Fibonacci and Prime Numbers" (20:16)
- Clip: "Investigating Numbers in the Natural
World" (03:36)
- Clip: "Investigating Fibonacci Numbers"
(05:45)
Web
Materials
- Several sets of an assortment of flowers, twigs with leaves,
pinecones and bunches of pine needles that show Fibonacci numbers
occurring in nature
- Optional: a cauliflower, an African violet plant and a pineapple.
If you can get it, bring in a chambered Nautilus seashell that
has been cut in half.
- Copies of the Fibonacci and the Rabbits Worksheet (at end of
lesson plan)
- Computer and projector
Prep for Teachers
When using media, provide students with a Focus for Media Interaction,
a specific task to complete and/or information to identify during
or after viewing of video segments, Web sites or other multimedia
elements.
Download the video clips that you will be using from OPB's TRS
Video On Demand. You can preview them by streaming them on the Video
On Demand site, but when showing them in the classroom, you'll want
to use a downloaded copy - either on the computer hard drive or
burned onto a CD - because you have more control that way. Make
sure you have a copy of the free Windows Media Player to use for
watching OPB's TRS Video On Demand clips. For many clips, it is
also possible to use QuickTime Player.
Be familiar with the parts of the video that will be shown and
the cues within the videos at which you will start and pause.
Cue the first video clip, "Investigating Numbers in
the Natural World" (03:36), from the video, "Mathematical
Eye: Fibonacci and Prime Numbers" (20:16), to the section right
after the title by using the scroll bar, then pause it at
approximately 00:10.
Explore the two Web sites to be used. Examine the links and decide
how much time and detail you want. Bookmark the sites so that you
can get to them quickly during the lesson. Divide students into
enough groups so that each has a set of natural materials.
Introductory Activity
Students will notice the Fibonacci series through the following
series of video clips and activities:
Step 1: Without telling students anything at all about the
Fibonacci series of numbers, show them the following video clip.
Before starting the clip, provide your students with a Focus
for Media Interaction by asking them, "What do you think
the kids in the video are doing?" Play the video clip,
"Investigating Numbers in the Natural World" (03:36),
from the video, "Mathematical Eye: Fibonacci and Prime Numbers"
(20:16), from the point where you cued the video as the camera is
panning up to the bridge and showing the students on the bridge
counting something. (Remember, you are skipping the first part with
the title, since it mentions Fibonacci and some students may have
already heard of the series.) Pause the video at approximately
00:28 when the boy writes something on his paper. (Ask students
what they think is going on. You might have them tell a neighbor
first and see if the class can come to a consensus. "Counting
something" is probably obvious, but try to get them to predict
what.)
Provide your students with a Focus for Media Interaction
by asking them to watch for a chance to count the scales on a turtle's
back. Play the video as it shows the turtle until about 00:37.
Pause the video to give students a chance to count the scales
(there should be 13), then play. Pause after the narrator
says, "
Do you think it crops up anywhere else?"
(00:46) Ask the students what they think. If 13 seems like a strange
number, what would be a less strange natural number? Where else
might they expect to find 13?
Step 2: Tell students they are going to investigate what
numbers do appear in nature and keep track. They should work in
groups with one student recording the results. Give each group a
set of natural materials. Include flowers, sets of pine needles,
twigs with leaves still on them and pinecones. (Prepare ahead of
time to have objects with Fibonacci numbers of things, not the exceptions
to the rule.) Have students count and write down the numbers they
find represented on the object and list in what ways they are represented.
They should be coming up with things like number of petals, number
of leaves on a twig, number of scales in a pinecone and number of
pistils and stamen on a flower.
After the list is complete, compile all group lists into a master
list put into numerical order. Discuss any patterns they notice.
Students may or may not at this point be able to spot similar numbers.
Ask them, "Did the number 13 come up again? Did it come up
in your flower petal counts? What do you think is going on? Is there
a pattern you can describe?" Take down ideas.
Tell students, "Let's look at another way to view this pattern
- one that has been around since the 13th century
"
Learning Activities
Step 1: Introducing Fibonacci
Provide your students with a Focus for Media Interaction
by asking them, "What did the Europeans use to count before
they had the digits 0-9? (Roman numerals) Go to your bookmark for
the Web site, http://plus.maths.org/issue3/fibonacci/,
to show a picture of Fibonacci and a brief biography. Show on your
screen the section, "Have you ever wondered where we got our
decimal numbering system from?" through the quote from Fibonacci's
book. Allow students time to discover the answer to your question
and then discuss it.
Step 2: Introducing the Fibonacci Sequence
Provide your students with a Focus for Media Interaction
by asking them to look for a pattern in the series of numbers for
which Fibonacci is famous. Scroll past the "Root Finding"
section to the "Fibonacci Sequence" section. Ask students
to study the numbers in the Fibonacci series and see if they can
spot a pattern. Depending on your class, you can either leave the
answer showing ("Add the last two numbers to get the next.")
or you can arrange the screen so that statement is just past the
top where it can't be seen.
Provide your students with a Focus for Media Interaction
by asking them, "What do you think this rabbit problem has
to do with this sequence of numbers?" Direct their attention
to the rabbit problem with which Fibonacci was challenged.
Step 3: Solving the Rabbit Problem
Provide your students with a Focus for Media Interaction
by asking them to watch for some of the same biographical information
they just saw on the Web site. Use the beginning of the video clip,
"Investigating Fibonacci Numbers" (05:45), from the video,
"Mathematical Eye: Fibonacci and Prime Numbers" (20:16),
to support this part of the lesson.
Play from the beginning of the tape. Pause after
the narrator says, "
How many rabbits will there be by
the end of the year?" Ask for feedback on the biographical
information (Pisa, Italian mathematician, 1200s, book called Liber
Abaci).
Tell students they are going to solve the rabbit problem.
Give each student a copy of the Fibonacci and the Rabbits Worksheet.
Have them work either independently or in groups to come up with
an answer. (The answer is 144 pairs of rabbits.)
Ask students if any of the numbers they came up with during the
rabbit problem look familiar. Refer back to their count of natural
objects and the numbers in the Fibonacci sequence. Explain to the
students that the set of numbers that Fibonacci came up with as
he solved the rabbit problem appears in all sorts of ways in nature.
Provide your students with a Focus for Media Interaction
by asking them to check their work along with the narrator in this
next section of the video. You may need to remind them that each
block represents a pair of rabbits, not a single rabbit.
Play the video clip from where you left off with the narrator's
question. It shows students solving the rabbit problem with blocks.
The numbers should look familiar to your students after their work
with the Fibonacci and the Rabbits Worksheet.
Step 4: Fibonacci and the Natural World
Go to Dr. Ron Knott's Web site at http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fibnat.html#Rabbits.
Rabbits: Show students the rabbit diagram after the "Fibonacci's
Rabbits" heading. A solution diagram for 10 months can be found
on this Web site. Dr. Knott also brings up the problems with the
rabbit problem - no rabbits die; each pair has exactly one pair
of babies every single month starting at two months old and so on.
Discuss these shortcomings with the students but explain that the
numbers still appear in nature.
Spiral Shells: Scroll down about a third of the way through
the Web site (past the honey bees, cows and so on) to "Fibonacci
Rectangles and Shell Spirals." There is an animated drawing
that shows how a spiral shape can develop by using a series of squares
of progressively larger sizes. The size of a square's side is determined
by the sum of the sides of the last two squares. The animated drawing
is on the left and on the right is a still drawing. Allow it to
play while you point out what is happening as the spiral grows,
referencing the still drawing as needed.
Once students seem to have a grasp of the creation of the spiral,
you can begin to show them how the spiral appears in nature. The
first stop is the cross section of a chambered Nautilus shell on
that same section of the site. If you have one of these shells to
bring in and share, so much the better!
Plants: Continuing to scroll down, there are examples of
branching plants, petals on flowers and seed heads. Depending on
how much time you have and the level of detail you want to go into,
there are links that can be followed for more pictures that illustrate
the appearance of Fibonacci numbers.
Pinecones: The next section helps students see how the scales
of pinecones are arranged in Fibonacci numbers of spirals. You can
click on buttons to see the two lines of spiral scales highlighted.
Pass around real pinecones (from the sets of natural materials in
the Introductory Activity) so students can compare them with what
is on the screen.
Branches: The next section is about how the branches of
plants are arranged in a spiral format so that each leaf gets the
maximum amount of sunlight. The picture based on the African violet
that you can get to by clicking on the "picture" word
link is a very good illustration of that. The "leaves per turn"
section here relates to ratios of Fibonacci numbers, which you can
use as an extension of this basic lesson. Show a real African violet
if you have one.
Vegetables: Finally, there is a section on spirals in vegetables,
illustrated by the cauliflower. Clicking the buttons will highlight
the two spirals on the cauliflower. Again, a real cauliflower can
also be examined by students, as can a pineapple.
Culminating Activity
Students will apply what they have learned about Fibonacci patterns
and numbers to the human body.
Provide a Focus for Media Interaction by asking students
to decide whether humans have Fibonacci numbers built into them.
Scroll to the final section on Dr. Knott's Web site called "Fibonacci
Fingers?" and let students think about their hands. Explain
the Phi is the Golden Ratio, which can be found by dividing any
Fibonacci number by the one right before it. It should come out
to be about 1.6, with accuracy getting closer and closer to "The
Golden Number" as you divide larger Fibonacci numbers. This
is explained by Dr. Knott in the "Fibonacci numbers and the
Golden Number" section.
Have students take on Dr. Knott's challenge: "Why not measure
your friends' hands and gather some statistics? I'd be interested
in your results if you want to email them to me." (fibandphi@ronknott.com)
Cross-Curricular Extensions
Other Web Sites
- This is another of Dr. Ron Knott's sites that provides many
links to sites related to Fibonacci numbers.
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fib.html
- This is a history of math site that includes a biography of
Fibonacci.
http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Fibonacci.html
- This site has beautiful pictures that are related to Fibonacci
spirals by artist Edward S. May.
http://www.moonstar.com/~nedmay/chromat/fibonaci.htm
- This British site by Brantacan explains Fibonacci numbers and
how they are related to flowers, pinecones, pineapples, palm trees,
suspension bridges, spider webs, dripping taps, CDs, your savings
account and quite a few other things.
http://www.branta.connectfree.co.uk/fibonacci.htm
- This National Council of Teachers of Mathematics site uses a
children's picture book, Bunches and Bunches of Bunnies,
to lead into the Fibonacci rabbit sequence. It includes historical
information on Fibonacci as well.
http://www.nctm.org/wlme/wlme6/supp_eight.htm
Science
- Further explore Fibonacci numbers in nature. Challenge students
to find other patterns of numbers in crystals and rocks, in the
distance of planets from the sun and so on.
Music
- The keys on a piano are set in Fibonacci numbers: 2 black keys
plus 3 black keys make 5 black keys; 8 white keys; 13 keys in
all. Chords can be related to Fibonacci numbers. Explore making
Fibonacci music by playing notes only a Fibonacci number apart.
Art
- Using the Edward S. May artwork on the Web site listed above
for inspiration, have students create spiral art that uses the
Fibonacci spiral. Instructions for drawing the spirals can be
found in Dr. Knott's "Fibonacci and Shell Spirals" section
that you taught above.
- Teach the Golden Rectangle to students. A Golden Rectangle has
sides with a ratio of Phi. A lot of information can be found on
the Web sites listed above.
Architecture
- Have students look for the Golden Rectangle in bridges, buildings
and monuments.
Language Arts
- Have students write poetry with a Fibonacci number of lines,
such as a haiku.
History
- Research the 1200s. (This was when the Leaning Tower was built
in Fibonacci's hometown of Pisa.) Have students try to add, subtract,
multiply and divide with Roman numerals as they did before Fibonacci
introduced Arabic numbers.
Community Connections
- Walk around the school's neighborhood or a wild area and look
for Fibonacci patterns.
- Talk to an artist about how he/she uses the Golden Rectangle,
which includes Fibonacci ratios.
- Have a botanist or zoologist come in and talk about Fibonacci
numbers and his/her specialty.
- Include a Fibonacci problem as part of a Math Trial around the
school or neighborhood.
Name: _______________________
Fibonacci and the Rabbits
Beginning with a single pair of rabbits, if every month each productive
pair bears a new pair, which becomes productive when they are 1
month old, how many rabbits will there be after 12 months? The key
to success is to remember that these mythical rabbits are not able
to have babies until they are 1 month old and then it takes 1 month
of pregnancy before the babies are born. So it is 2 months between
the time a pair of rabbits are born and the time they first give
birth. The first 3 rows are done for you. Use the chart on the other
side of the paper to help you complete this table.

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