If k = 3, then the whole numbers less than 3 are 2, 1, and 0. There are 3 whole numbers less than 3.
If k = 10, then the whole numbers less that 10 are 9, 8, 7, 6, 5, 4, 3, 2, 1, and 0. That's 10 whole numbers less than 10.
It appears that there are k whole numbers less than the whole number k.
