Question

what number is 1,999,999 less than the smallest 10-digit number?

Answer 1

The smallest 10 digit number is 1000000000 
so 
1000000000-1999999
=998000001

Answer 2

 Number which is 1,999,999 less than smallest 10 digit number means that -
Smallest 10-digit number - 1,999,999
1,000,000,000 - 1999,999 = 998000001