How to check how many times one number appears in the second number?

I'm new in Java and I have a task that's going like this: Generate one number between 0-9 and a second number between 10-99. You need to check how many times the first number appears in the second number. (For example: The first number is 5 and the second one is 55 so the first number (5) apears 2 times in the second number (55) ). Btw, you need to make it without arrays.