She started figuring out how to add. It was so unexpected. We were stopped at a red light, and she noticed that there were two lights in front of us, and two turn signal lights off to the side. She said, "Mommy, look! Two lights and two lights. There's four!" And she put two fingers up from her right hand and two from her left hand and put them together in front of her. So, we've been looking at other things now and then that we can put together. She mostly notices it with the stop lights for some reason. She was also doing it with some poker chips a few nights ago. I've pointed it out 2 or 3 times when I noticed something she was doing that she was adding together, but mostly she's been noticing it herself.
It's interesting because she can't count to 20 yet, and only counts to 10 without a mistake about half the time. Which is interesting in itself because for a while she could do that, but she seems to have forgotten. But I have read that often kids will seem to lose old skills when they are picking up new ones and then suddenly get them back. Anyway, it just goes to show that the "pre-requisites" for certain skills aren't necessarily required.
She will say things like "Look, mom, two and one makes five." But with her fingers she'll be doing two on one hand and one on the other hand to make three. So, she is starting to grasp the concept, but doesn't always have the right word to match with the number of items. So I'll just smile and say "Yep, three!" and she agrees with me like she knew that all along, because that's what she meant after all, just not what she said. Or maybe she really did mean five, but she trusts me when I say three. It's all relaxed and fun and there won't be a test, so it's easy to just make a mistake and then learn something new and move on.