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Stern Structural Arithmetic and Fractions

Temple AryLois Feldman

www.sternmath.com

International Dyslexia Association Conference March 9, 2010

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Agenda

1. Discuss: What’s hard about teaching fractions?

2. Fraction story where each pair will cut fractions.

3. Play 2 fraction games.

4. Discuss what you learn about fractions from the

games.

5. Show you a preview of a new fraction book.

6. Show you a money game that connects fractions,

decimals and percents.

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What’s Hard About Fractions ?

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Candy Bars

• Imagine your favorite candy bar

• I have a candy bar and I’m about to take a bite….

One Whole

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What is another name for a whole?

one halfone half

One Whole

I have a candy bar and I’m about to take a bite….

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Fourths

• What is another name for a whole?• What is another name for a half?• Which is bigger – a fourth or a half?

One Whole

I have candy bar and I’m about to take a bite….

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Eighths

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12

One Whole

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14

14

14

18

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18

18

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Hiding Game

What piece is missing? Variation: Hide two pieces

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Hiding Game

• What does one think about when figuring out which piece is hidden?

– What row?

– How many pieces is the whole cut into?

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Fraction Lotto Game

Numerators

322111

Denominators

Fraction Lotto Box

84 4 8 82

Fraction Pieces

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The Fraction Lotto Game

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Putting Away Game

• When the one student wins, play the putting away game.

• The students whose board is not full have a head start

When removing the pieces, you are, in fact, subtracting:

1 = 44

41

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Adding Same Denominator

Book 3, p 105

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Adding Different Denominators

• Draw two denominator cards• Draw two numerator cards

2 1

4 8

Where do I want to put the numerators?

At the end of the game (so I can fill the game board),allow them to pick just pick one numerator & denominator

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Double or Half

1 x 2

Put 3 on sides of a die:

•Each person has an empty Lotto Board•Roll the die (1/2 x) •Pick a card (1/4)•“½ of ¼ equals 1/8”•Student puts a 1/8 size piece on the lotto board•Students may exchange pieces at any time•Need exact amount to fill board

Make 6 cards ¼, ¼, ½, 2/4, 3/4, 1

Put 3 on sides of a die:

2 x

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Division of Fractions

How many fourths are in a whole?

1 2 3 4

Fractions are smaller than a whole…so there are 4.

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Division of Fractions

• Division of Whole Numbers– 30 divided by 6

• Easy to demonstrate in the number track as containment• How many 6s are going to fit into 30?• Able to show that five 6-blocks fit into this space

• Division of Fractions– ½ divided by ¼

• How can we demonstrate containment?• How many 1/4s are going to fit into 1/2

1/2

1/4 1/4

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Another Example

How many 1/8 yard pieces are in ¾ yard of material?

¾ yard of material and cut into 1/8 yard pieces

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..34

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$3 divided by 34

1. Make into quarters 2. Chunk intogroups of 3

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3 ..

34

3 ..

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3Multiply 3 x 4

What do I have to do?

How many groups?Total # of parts

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Peg’s New Fraction Book

• Peg's book. PDF

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