How Many Numbers Do You Know?!

While trying to guess a security code on dad's old breifcase..
We were guessing for a while and weren't getting close.
Me: How many numbers are in the code? Four?
Dad: 3
Mom: 4! (she was guessing too.)
Me: Dad just said 3!
Dad: (Laughing)

A little later...we still weren't getting close even after dad told us the first number.
Me: Is it a number we know?
Dad: What number do you not know?! (More laughing.)

Good point.

In my defense, it was 1am when we were having this discussion and I meant if it was a number that is significant to our lives. In the end I ended up guessing the number!