How many 6-digit numbers are there in all?

There are 6-digit numbers from 1,00,000 to 9,99,999, inclusive.

To find the total count, you can use the formula:

Total numbers = (Largest number) - (Smallest number) + 1

Largest 6-digit number = 9,99,999

Smallest 6-digit number = 1,00,000

Total 6-digit numbers = 9,99,999 − 1,00,000 + 1

Total 6-digit numbers = 8,99,999 + 1

Total 6-digit numbers = 9,00,000

Hence, there are 9,00,000 six-digit numbers in all.