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

Findnig the smallest number of four digit and the largest number of three digits

We know that,
The smallest number of 4 digits is = 1000
The largest number of three digit is = 999

Finding the difference between obtained number

Difference $=1000-999=1$

Thus, the difference between the smallest number of four digits and the largest number of three digits $=1000-999=1$