Question

Find the sum of the greatest $7$-digit number and the smallest $5$-digit number.

Answer 1

Finding the required sum:

Greatest $7$-digit number$=9999999$

Smallest $5$-digit number$=10000$

Sum of the greatest $7$-digit number and the smallest $5$-digit number$=9999999+10000=10009999$

Hence, sum of the greatest $7$-digit number and the smallest $5$-digit number is $10009999$.