five hundred and something

Last night I hear Big Kid shouting from upstairs: "Five hundred...and..."

I couldn't make out the exact number he was rattling off and I had no clue what he was talking about until i asked M.

Me: "What did he say?"
M: "Oh, we were talking about hair cuts upstairs."
Me: "Huh?"
M: "I said something to him about having a hair cut and Big Kid asked me how many hair cuts I've had in my lifetime. I told him I had maybe 10-12 haircuts a year. then I told him how old I am. I guess he finally finished his calculations and that's his answer."
Me: "oh."

p.s. i circled yes, and we bought the shoes yesterday.