Final answer:
To determine the number of positive integers between 1000 and 9999, inclusive, subtract 1000 from 9999 and add 1, resulting in 9000 positive integers.
Step-by-step explanation:
The question is about determining the number of positive integers between 1000 and 9999, inclusive. To find the answer, we use a simple subtraction method. The last number in the range is 9999, and the first number is 1000. We can calculate the total number of integers in this range by subtracting the first number from the last number and then adding 1 (because the range is inclusive).
9999 - 1000 = 8999
Then, to include the first number in the count, we add 1:
8999 + 1 = 9000
Thus, there are 9000 positive integers between 1000 and 9999, inclusive.