Vidhi writes the smallest $6$-digit number and Ridhi writes the greatest $7$-digit number on the blackboard. Their Maths teacher finds the difference between the smallest $4$-digit number and the sum of the two numbers written on the blackboard. What would be the answer?

If a number is formed by interchanging the digits at tens and thousands places of $7939$, then which of the following is correct?

The number $90406092$ is written in International System of Numeration as

Which of the following statements is incorrect?

$80325901$ can be written in words as

Latika's monthly salary was $₹30525$. She spent $₹1800$ and saved the rest. How much did she save in a year?