Expert: Josh - 2/3/2006

Question
When subracting
131940 - 131802 = 138

But, when a true or manual count from 131802 thru 131940 is done, the outcome is 139.

Is this inclusive stuff?
Please explain...

Answer
Yes Monie, you are pretty much spot on.
When we perform subtraction, this is an "exclusive" operation. However, when we consider the number of integers in the range from A to B inclusive, the answer is (B-A)+1, assuming that integer B is greater than integer A.

We can specify exclusive intervals using the following notations.
Suppose we want to specify all integers from 1 to 10, excluding 10, we can write [1,10). The closing parenthesis on the right indicates an open-ended interval to the right.
Similarly, we can specify all integers in the range from 1 to 10, excluding "1" itself by writing (1,10]. This consists of 9 numbers. We effectively count from 1 to 9.
To specify all integers from 1 to 10, without any exclusion, we use square parentheses and write [1,10].

Hope this makes sense.

Cheers,