Odd
Numbers
. 
:. 
::. 
:::. 
::::. 
:::::. 
::::::. 
and so on 
1 
3 
5 
7 
9 
11 
13 
and so on 

ALL numbers NOT in the 2 times table
are odd numbers

ALL odd numbers leave a remainder of
1 if divided by 2

ALL odd numbers end in 1, 3, 5. 7 or
9

Examples
We can tell that 71 is odd because it ends in 1
We can tell that 123 is odd because it ends in 3
We can tell that 2345 is odd because it ends in 5
We can tell that 64747 is odd because it ends in 7
We can tell that 567989 is odd because it ends in 9 
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