That being said, it is really easy to teach babies math on a daily basis.  I have a CD that teaches basic addition through song.  I got this for my older children, but the babies seem to learn whatever the older children are doing anyway.  I sing a simple addition song to my children.  It goes like this: 

1+1 is 2

2+2 is 4

3+3 is 6

and so on.  It goes up to 10+10 is 20.  The fascinating part of this is that I can ask my child what 8+8 is, and they will quickly say 16.

I took this a step further just last week.  I asked my daughter if she wants to play M&M math.  I sing the adding song to her and demonstrate the quantities with candy.  Then I teach her subtraction and she gets to eat them.  We start with 10-1, then she eats one and we determine that there are 9 left.  This is fun and interactive way to expose toddlers to math.  For people who are more health conscious, they can use raisins.