Children learn how to count before they learn the real, mathematical meanings of the numbers. Here's a short example from my two-year-old daughter.
There's five eggs! One... 'leven... eight... nine!
She can usually get the order of the numbers right, but she still doesn't realize that whatever number you stop at is the number that can refer to the group of things you're counting as a whole. Lately, she's been using the number two pretty consistently to refer to any group larger than one. That's not bad, I think.