When adding or subtracting,
whether your sum or difference 
is odd or even depends 
on the numbers you add or subtract.

You will get Even Sums
When the numbers you add 
are 
BOTH EVEN
or
BOTH ODD

4 + 4 = 8
6 + 8 = 14
or
3 + 3 =  6
7 + 5 = 12

You will get Odd Sums
When the numbers you add
have
One number ODD and the other is EVEN

3 + 4 = 7
9 + 6 = 15
or
10 + 2 = 12
16 + 4 = 20

You will get EVEN DIFFERENCES
When the numbers you subtract 
are 
BOTH EVEN
or
BOTH ODD

20 - 4 = 16
6 - 2 = 4
or
19 - 3 =  16
27 - 5 = 22

You will get ODD DIFFERENCES
When the numbers you subtract
have
One number ODD and the other is EVEN

3 - 4 = 7
9 - 6 = 15
or
22 - 5 = 17
8 - 3 = 5

Remember:       
Whether your sum or difference 
is odd or even depends 
on the numbers you add or subtract.

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