Out of the blue one night a few weeks ago -
DS8: "I know a number that you should never do in binary."
Me rather confused: "Uh what"
DS8: 132
Me still confused: "Uh ok. Why?"
DS8: "I'll get in trouble"
Me: "I give you permission and you won't get in trouble this one time."
DS8 with a smirk then holds up both middle fingers at me and then explained how each finger was a digit and 0010000100 == 132

When I told this to DH he laughed and explained that they had been using binary and their fingers to keep track of the score at DD's soccer game earlier. I asked if he had gone up that high or if he had helped him figure it out and he said they had only done up to 15.

To add to this, we were at a science museum today and they had a thing on binary. I spent 5 minutes trying to explain it to my mom and I'm pretty sure she was just saying she got it to get me to shut up in the end. Then DS came over and said it's easy grandma and rattled a bunch of them off with his fingers for her and then explained it. She looked over at me while this was happening with a hilarious look on her face. I think she's starting to get it.