Shell Script to Find Sum of Digits of a Number

Q. How do I write Shell Script to find Sum of digits of a Number
Ans:

#!/bin/bash
echo -e "enter the number"
read n
sum=0
a=$n
while(($n >0))
do
x=`expr $n % 10`
sum=`expr $sum + $x`
n=`expr $n / 10`
done
echo "the sum of $a is $sum"


Output

Enjoy :)