4A Fractions

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4A Fractions
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4 and one quarter plus some number is 8 and three
quarters. Find that number
4 ¼ X 8 ¾
-4 ¼ -4 ¼
X 4 ½
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(No Transcript)
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Which is larger 3/5 or 8/12
3/5 .6 8/12 .666666
3 8 5 12
312 85 512 125
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3/4 can 1 day
Mrs. Fox has two dogs, Baron and Me-Too. Baron
is a big dog and eats 3/4 can of dog food each
day. Me-Too is a smaller dog and eats 2/3 of a
can of dog food each day. If dog food costs 3
for two cans, how much will it cost to feed the
dogs for 12 days? Use words, numbers, or pictures
to explain your thinking.
3 cans 4 days
2 cans 3 days
3 dollars 2 cans
3 dollars 17 cans 2 cans
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• SCORING CRITERIA
• 4  WELL DONE
• correct
• very complete
• very clear
• 3   FINE TUNE
• mostly correct
• mostly complete
• mostly clear
• 2   FINISH OR FIX
• several errors
• partly complete
• partly clear
• 1   START OVER
• major errors

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3
1 ?
8
4
2 ?
9
1
3 ?
10
2
4 ?
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A man spent one third of his money and then lost
two thirds of the remainder. He was left with
12. How much did he start with?
12
6
54
no
no
no
no
no
6
6
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HOW TO COMPARE FRACTIONS

• Introducing
• common denominator
• least common denominator
• like fractions
• unlike fractions.

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Compare Fractions
The fractions 2/4 and 3/4 have the same
denominator. Fractions with the same denominators
are like fractions.
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Compare Fractions 3
9/16 and 7/16 are like fractions. The numerator 9
in 9/16 is larger than the numerator 7 in 7/16,
making 9/16 larger than 7/16 .
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How To Multiply Fractions

• Introducing
• factor
• product
• reciprocal
• inverse
• identity
• inverse

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Multiply Fractions

• The product 9/8 can be written in fraction form
  1 1/8

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Multiply Fractions

• It is easy to tell the product 4 4/5 from
  this picture. Notice the 4 complete circles and
  the 2/5 2/5 circles for a product of 4 4/5.

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Multiply Fractions 8

• To find the reciprocal of a fraction, replace
  the denominator with the numerator and the
  numerator with the denominator. The reciprocal
  or inverse of 2/1 is 1/2.

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Multiply Fractions

• The factors 1 1/4 and 4/5 are also
  reciprocals. As you can see, multiplying 5/4 by
  4/5 gives a product of 1. If you are asked to
  invert or write the reciprocal of 5/4 you will
  write 4/5 .

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Multiply Fractions

• Both factors are greater than 1. Notice the
  product is greater than 4 x 1 but less than 5 x 2
  by rounding down and rounding up both factors.

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Multiply Fractions

• You can tell by the picture that there are 4
  whole units, five 1/2 units, and one 1/4 units.
  The sum of the units is 4 5/2 1/4 6 3/4 .

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ComparingFractions  
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FractionPie  
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Fraction Sorter
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fraction mult.
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Fraction Man  
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Fresh Baked Fractions  
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Cantor's CombHilbert Curve GeneratorAnother
Hilbert Curve GeneratorKoch's SnowflakeSierpinsk
i's TriangleSierpinski's Carpet
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USU Tangrams  
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Enchanted Tangram
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Interactive Tangrams 
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KidsCom Tangrams    
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Tangram Challenges   
Task Is it possible to complete all these tasks?
Try these tangram challenges with the virtual
tangrams Make a square using only one tangram
piece. Make a square using two tangram pieces.
Make a square using three tangram pieces. Make
a square using four tangram pieces. Make a
square using five tangram pieces. Make a square
using six tangram pieces. Make a square using
all seven tangram pieces. Which of these figures
can you make using all seven tangram pieces? A
trapezoid A rectangle that is not a square A
parallelogram that is not a square A triangle