Order means to arrange numbers from least to greatest or from greatest to least.  When ordering decimals, it is important to first compare the whole numbers.  Then compare the numbers in the tenths column.  If they are the same, compare the numbers in the hundredths column.  

Example 1:  Place the following numbers in order from 
                  least to greatest.

           2.9          1.9          1.09          2.09

First compare the whole numbers.  The numbers with the whole number one will be first in ordering least to greatest.

              1.9          1.09          2.9          2.09

Next compare the numbers in the tenths column.  

              1.9          1.09          2.9          2.09

Zero is less than one, so 1.09 will come before 1.9 and 2.09 will come before 2.9.  

You now have your answer ordering the decimals 
from least to greatest.

 1.09   <   1.9   <   2.09   <   2.9

Example 2:  Place the following numbers in order from 
                  greatest to least.

                   4.23          5.30          4.26          4.33  

First compare the whole numbers.  The numbers with the whole number five will be first in ordering greatest to least.  

              5.30           4.26         4.23         4.33 

Next for all the numbers with the whole number four, compare the numbers in the tenths column.

                 5.30          4.23          4.26        4.33 

Three is greater than two, so you now have:

                 5.30           4.33          4.23        4.26 

Finally, there are two numbers with two in the tenths column, so you now compare the numbers in the hundredths column.

                 5.30          4.33          4.23        4.26

Six is greater than three, so you now have your answer ordering the numbers from greatest to least.

                 5.30   >   4.33   >   4.26   >   4.23