Script to convert numbers into equivalent words

#!/bin/bash
# Shell script to read a number and write the number in words. Use case
# control structure. For example 12 should be print as one two
# -------------------------------------------------------------------------
# Copyright (c) 2005 nixCraft project
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

echo -n "Enter number : "
read n

len=$(echo $n | wc -c)
len=$(( $len - 1 ))

echo "Your number $n in words : "
for (( i=1; i<=$len; i++ ))
do
# get one digit at a time
digit=$(echo $n | cut -c $i)
# use case control structure to find digit equivalent in words
case $digit in
0) echo -n "zero " ;;
1) echo -n "one " ;;
2) echo -n "two " ;;
3) echo -n "three " ;;
4) echo -n "four " ;;
5) echo -n "five " ;;
6) echo -n "six " ;;
7) echo -n "seven " ;;
8) echo -n "eight " ;;
9) echo -n "nine " ;;
esac
done

# just print new line
echo ""