Proceed from left to right, using the largest possible digit in each position.
i think 98765
9876543.
642
The number 9 is the greatest one-digit number.
fcfdfd
There is only one number and that is 123456.
What is the sum of greatest 3-digit 4-digit 5digit
The greatest 4-digit number with no repeated digits is... 9876
98765
The largest 5 digit number it can be is 99999.
987654
98,764
9876
987654
98,764
987654
9876543.
987654