DigitMania

This application is intended for real math lovers (schoolchildren, students, numberphiles etc.)!

Ask your friend in any instant messenger to perform simple 2 steps:
1/2) Write any number from 1 to 9;
2/2) Write any 3-digit number (from 100 to 999);
Enter this number and digit from your friend to the 'DigitMania' app.

The application search the shortest mathematical expression for any 3-digit number using only one digit and operations with it:
Addition, Multiplication, Subtraction, Division, Exponentiation and Concatenation (combining 2 digits in one number).

Send a shortest mathematical expression for a given number using the specified number to your friend.

Your friends will certainly appreciate your high knowledge of mathematics. Good luck !;)