My grand-daughter is not quite 20 months old. She started counting by rote several months ago and can count easily to 10 (although for some reason she often skips the number 1). Sometimes she keeps going into the teens. I thought this was astounding enough. But watch the video below to see true genius.
At first I'm trying to get her to count....that's my voice you hear. When she looks at me and realizes I'm not going to tell her the numbers, she picks out some numbers to tell me. She knows even more than she says here......but of course I couldn't get her to do it on camera. She says "seven" perfectly.......when she wants to!