Earlier quoted context omitted.
I’m fairly certain I was taught the unary counting system in either kindergarten or 1st grade. And I wasn’t even in an advanced course.
Timmy has 1 rock. Johnny gives Timmy 1 rock. Timmy now has 1 rock. Jenny gives 1 rock to Timmy. Timmy has 1 rock.
0 – one
00 – two
000 – three