Hard Riddles

A professor asked John to write down any multi-digit number. But, he put a condition, the number should not end with a zero.

John put down the number 96452.

Then the professor asked John to add up the five digits and subtract the total from the original number. John did and here is what he got:
96452 – 26 = 96426

The professor then asked John to cross out any one of the five digits and tell him the remaining numbers. John crossed out the 2 and told the professor the rest of the digits. John neither told the professor the original number nor what he had done with it. Yet, the professor told John the exact number he had crossed out.

How is it possible?