While your soon-to-be kindergartener probably won't be learning to add and subtract this year, he or she will be learning those skills next year, in first grade; and kindergarten math is about laying the groundwork for that [source: Miller].
He or she will be definitely working with numbers in the course of the year, and it's important to walk in on the first day knowing the basics. Counting to 10 is a big one, as is knowing whether a collection of, say, marbles or checkers contains one, two, three, four or five of those marbles or checkers.
If your child also understands the basic concepts of more and less, he or she is in an excellent position to succeed in kindergarten math.
Next, a skill you've probably been watching develop for years ...