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

Hint: In this question, we use the concept of largest and smallest digit number. The smallest six digit number is 100000 and largest four digit number is 9999.

Complete step-by-step answer:

We know the range of six digit numbers start from 100000 and end at 999999.
So, the smallest six digit number is 100000.
We also know the range of four digit numbers start from 1000 and end at 9999.
So, the largest four digit number is 9999.
Now the difference between the smallest six-digit number and the largest four digit number,
$
   \Rightarrow \left( {{\text{Smallest six digit number}}} \right) - \left( {{\text{Largest four digit number}}} \right) \\
   \Rightarrow 100000 - 9999 \\
   \Rightarrow 90001 \\
 $
So, the difference between the smallest six-digit number and the largest four digit number is 90001.

Note: Whenever we face such types of problems we use some important points. First we find the smallest six digit number and also find largest four digit number then their difference gives the correct answer.