Transcript Fractions

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A Great Big Piece of Fun
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Fractions were invented to
express numbers that are in
between whole numbers.
Fractions can show measures
between whole numbers on
rulers or scales.
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Fractions can name part of a whole
object or part of a collection of
objects.
whole
collection
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Fractions can express chance or
probability - 1 out of 3 chance
(1/3)
Fractions can represent division
¾ = 3÷4 = .75
Most fractions are fractions of
“something” referred to as the
whole, one, or unit.
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The number on the bottom of the
fraction is called the denominator.
The denominator tells you how
many parts the whole is divided
into.
5/9 = 5 out of 9 total pieces
(a little more than half)
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The numerator is the number on
the top part of the fraction.
The numerator names the
number of parts under
consideration.
½ = 1 out of 2 parts
*An hour is what fraction of a day?
*A minute is ______ of an hour?
*A second is _____of a minute?
*Four days is ______ of a week?
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*How many hours is:
*120 minutes?
*150 minutes?
*75 minutes?
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*The value of a fraction or piece of a
unit may have many names.
*To find another name for a fraction,
multiply the numerator and
denominator by the same number.
⅛=
⅛=
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(x2) 2/16
(x3) 3/24
*The value of a fraction or piece of a
unit may have many names.
*To find another name for a fraction,
divide the numerator and denominator
by the same number.
50/100 = (÷5) 10/20
50/100 = (÷10) 5/10
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*Fraction Frenzy
*To put fractions in order you need to
consider the value of the fraction, not
just the name.
*Remember that a fraction is a piece of a
unit.
*The denominator tells you how many
pieces in the total unit.
*The numerator tells you how many pieces
out of the total you are working with.
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*Think about the fraction falling between
the values of 0 and 1 on a number line.
0
----------1
*Would you place 2/16 closer to the 0, 1/2 or 1?
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*Think about the fraction falling between
the values of 0 and 1 on a number line.
0
----------1
*Would you place 1/8 closer to the 0, 1/2 or 1?
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*Think about the fraction falling between
the values of 0 and 1 on a number line.
0
----------1
*Would you place 9/15 closer to the 0, 1/2 or 1?
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*When you compare fractions, a few
rules will make the job much easier for
you.
*When all the denominators are the
same, all the pieces are the same size.
You only need to compare how many
pieces each fraction has (numerator).
6/8, 3/8, 5/8, 8/8
3/8, 5/8, 6/8, 8/8
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*When you compare fractions, a few rules
will make the job much easier for you.
*When all the numerators are the same,
there are the same number of pieces for
each fraction. Think of the size of the
pieces to compare. (Remember, the bigger
the number, the smaller the piece!)
2/7, 2/9, 2/5, 2/12
2/12, 2/9, 2/7, 2/5
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*Put the following fractions in order:
2/3, ¼, 1/3, ¾
¼, 1/3, 2/3, 3/4
3/5, 5/10, 9/20, 1/25
1/25, 9/20, 5/10, 3/5
3/7, 1/10, 7/8, 5/7
1/10, 3/7, 5/7, 7/8
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*Put the following fractions in order:
5/9, 2/5, 1/6, 9/10
1/6, 2/5, 5/9, 9/10
4/8, 4/7, 3/5,4/9
4/9, 4/8, 4/7, 3/5
Time to check your homework!
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For this activity, you will need a
partner.
Each pair will need 20 counters
and page 122.
We will be working together as a
class. Please do not work
ahead.
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On this sheet, there are three
types of problems:
• Whole and part are given and the
solution requires you to name the
fraction.
8 puppies and 3 of them are girls. What
fraction of the puppies are girls?
Complete problems 1 and 2
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Whole is given and the fraction is
named. The solution requires you to
name the part.
If Joe has 21 coins, how many coins
would be in 1/7 of his collection?
Complete problems 3, 4, and 7
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The part is given and the fraction is
named. The solution asks for the
value of the whole.
If $5.00 is 1/5 of the ticket price, what is
the total cost of the ticket price?
Complete problems 5, 6, and 8
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How can a ruler teach us about
fractions?
Each inch on a ruler is broken into
equal pieces. The inch would be
the unit or whole. The hash marks
between each inch would be the
fractions of the inch.
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One Inch
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One Half Inch
Each inch is broken into 8
equal pieces or eighths (1/8)
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One Half Inch
If each inch is broken down into eights,
how many eighths in one-half an inch?
If each inch is broken down into eights,
how many eighths in one-quarter an inch?
1 inch = 8/8
½ inch =4/8
¼ inch = 2/8
Look at your ruler. What fractional part is
each inch broken into?
How many different names can
½ have on your ruler?
How can we use a
ruler to help us add
fractions?