Find the difference between the largest six-digit number and smallest four-digit number.

Q. The difference between the smallest six-digit number and the largest four digit number is

Q. Find the difference between the largest five digit number and smallest three digit number.

Q. What is the difference between the largest number of five digits and the smallest number of six digits?

Q. Fill in the blanks:
The difference between the smallest number of four digits and the largest number of three digits =-=.