Count on Chemistry

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Count on Chemistry

• Presented by the MathScience Innovation Center
• Written by Theresa Meade

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What is a polymer?

• It is a long, long molecule!
• Polymers can occur in nature or they can be made
  by humans. Can you guess which of these are
  polymers?

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What is a polymer?

• It is a long, long molecule!
• Polymers can occur in nature or they can be made
  by humans.

This is a small molecule. It is not a polymer.
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What kind of math is here?

• Long chains mean adding the same thing over and
  over.
• How does that relate to math?
• Long chains can be hard to analyze. Sometimes
  its easier to look at the parts.
• How does that relate to math?

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Today we will

• Look at large pieces
• Look at the smaller pieces inside
• Think about changes
• And have fun with math and science!

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What is a polymer?

• A polymer has a repeating pattern inside it. That
  pattern is made of a few atoms joined together to
  make a monomer.
• Many, many monomers join together to form
  polymers. The number of parts determines what the
  whole looks like! Ethane, butane, paraffin, and
  polyethylene

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Ethane

• First discovered in 1834
• A component of natural gas

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Butane

• Liquid form
• Found in LPG bottles used in gas grills

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Paraffin

• Waxy solid
• Used in candles and has a low melting point

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Polyethylene

• Solid
• This is everyday plasticmilk jugs, detergent
  bottles, or any plastic

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Thinking

• How can we create a model for the parts of a
  whole?
• We will start with some basic materials. Get
  ready!

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Lets look at a model

• Label one end of a strip of paper 0.
• Fold, then open.
• What should we label the fold line?
• What should we label the other end?

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Lets look at a model

• Lets look at another strip of paper.
• Label one end with 0 again.
• Fold.
• Without unfolding, fold the paper one more time.
• Unfold your strip.
• How many pieces all together?

1
0
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Lets look at a model

• Do you remember the steps? What do we do first?
• Fold your paper. Without out opening, fold it
  again. Now fold one more time.
• How many pieces do you predict there will be?
• What should we label the end?
• How many parts all together?

1
0
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Lets look at a model

• Lets make one more fraction strip.
• Remember the process?
• Label the end with 0. Fold the strip. This time
  fold it a total of 4 times without opening.
• How many pieces do you predict there will be?
• Open and look!

1
0
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Guided Practice

• Dont answer any of the questions yet! Well do
  these together in just a moment!
• So which one is larger, or ?
• How do you know?

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Guided Practice

• What are equivalent fractions?
• Yes! They are two different ways to name the same
  amount!
• Write some of the equivalent fractions we talked
  about on the lines in Part 1 of your Data Sheet.
• What are some of the numbers you wrote?

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Guided Practice

• What happens when you add ?

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Guided Practice
-
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Guided Practice

• Work with a partner to figure out problems 3 and
  4.

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Guided Practice

• I have

I want to add
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Guided Practice

• I have

I want to add
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Guided Practice
?
?
?
?
?
?
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Saving your work

• Use a glue stick to save all of your fraction
  strips.

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What if

• you didnt have fraction bars?
• Number lines can help you think about fractions!

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Number lines
1
0
When you add fractions with the same denominator,
draw one line. Find your starting point and
decide how many hops to take to get an answer.

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Number Lines
Step 1 Draw two number lines since you are
adding numbers with two different denominators.
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Number Lines
0
1
1
0
Step 2 Decide how to mark your number lines.

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Number Lines
0
1
1
0
Step 3 Find an equivalent fraction to use for a
starting point.

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Number Lines
0
1
1
0
Step 4 Add!

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Time to work with your partner

• You and a neighbor will work together to complete
  the rest of your data sheet.
• There is a front and a back, but dont worry if
  you dont have time to finish!
• Remember to work like a mathematicianbe
  accurate, take your time, and talk to your
  partner.

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Answers?

• How did you do?

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Why look at parts of the whole?

• Many scientists do exactly what you did!
• Think about genetics! We look at part of the DNA
  strand.
• Think about creating synthetic vitamins. We look
  at part of the molecule and recreate it!
• Think about making better plants and
  cross-breeding to get new varieties of roses.
• Its all about the parts!

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Now lets look at polymers again

• What do those long strings of monomers do?
• They have some very interesting properties!
• Its time for a demonstration!

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Did you enjoy polymers?

• Chemical engineering uses math and the art of
  putting things together to create and discover
  new compounds.

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Thank you!