MathDB

In my calculator, one of the keys from

1

9

does not work properly: when you press it, a digit between

1

and

9

appears on the screen that is not the correct one. When I tried to write the number

987654321

, a number divisible by

11

appeared on the screen and leaves a remainder of

3

when divided by

9

. What is the broken key? What is the number that appeared on the screen?

Problem Statement