What is this series?

Rachel was reciting some numbers at dinner tonight
3, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

Me: Hey do you know how to count by 10's now?
Rachel: Yes I just did.
Me: Then why did you say 3 and 5?
Rachel: I was counting by the numbers you can count to.
Me: What do you mean?
Rachel: You know you can count to 3 or 5 or 10 or all the other numbers.