S K Gupta and Anubhuti Gangal Solutions for Exercise 10: Mental Maths

What is the smallest $3$-digit number with unique digits ?

Write the smallest $3$-digit number which does not change if the digits are written in reverse order.

Subtract the successor of $99$  from the predecessor of $201$.

Form the largest and the smallest  $4$-digit numbers,using each of the digits $9,3,0,7$.

Every natural number is whole number, true or false.

Every whole number is a natural number, true or false.

Is the whole number $1$ has $0$ as predecessor.

The difference of any two consecutive whole numbers is $2$, state true or false.