comparing ordering fractions 4th grade

Document Sample
comparing ordering fractions 4th grade Powered By Docstoc
					Objectives
  TSW compare and fractions with like and
  unlike denominators using fraction pieces,
  drawings, and the butterfly method.

  I can compare and order fractions with
  like and unlike denominators.
      Important Words
Numerator
Denominator
Like
Unlike
To compare fractions you
can draw a picture or use
 the “Butterfly” method.
Draw a picture       Use >, <, or =.




            3    <   5
            4        6
Comparing with like denominators
3    2          1     4          2       1
7    7          6     6          3       3

You have to look at the parts and find
which one is bigger.
“Butterfly” method       Use >, <, or =.
             9       <    10
             3            2
                     <
             5            3
“Butterfly” method       Use >, <, or =.
             12      >    10
             3            1
                     >
            10            4
Lesson 2
 To order fractions you
 can draw a picture or
use the Least Common
  Denominator (LCD).
                       Order :
Draw a picture   least to greatest
                          3
                          4
                           1
                           2
                           5
                           6
Order the fractions from
   least to greatest.
   1     3   5
       ,   ,
   2     4   6
One way to compare or
 order fractions is to
express them with the
 same denominator.
Any common denominator
 could be used. But the
     Least Common
   Denominator (LCD)
 makes the computation
         easier.
  The Least Common
  Denominator is the
Least Common Multiple
 of the denominators.
     LCD = LCM
Use LCD
  List the fractions in order
  from greatest to least.
          1 7 5 2
            , , ,
          6 12 9 3
Use LCD
 Step 1: Find the
 LCM of the
 denominators
          1 7 5 2
           , , ,
          6 12 9 3
Find the
LCD:
      6, 12, 18, 24, 30, 36, 42, 48…
     12, 24, 36, 48 …
      9, 18, 27, 36, 45 …
      3, 6, 9, 12, 15, 18, 21, 24,
         27, 30, 33, 36 …
                        LCD = 36
Step 2: Write
equivalent
fractions. x 6
         1 6         7 x 3 21
                       
         6 x 6 36   12 x 3 36
         5 x 4 20   2x 12 24
                      
         9 x 4 36   3x 12 36
Step 3:
Compare the          G   L
numerators
       1 6     7 21
                  36
       6 36   12
       5 20   2 24
                 36
       9 36   3
Use LCD

            In order from
          greatest to least:

            2 7 5 1
             , , ,
            3 12 9 6

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1487
posted:5/26/2012
language:English
pages:21