Numbers

When getting Cameron from his bed this morning, he was counting the pictures on his quilt. He counted to ten and then surprised me by saying eleven, twelve, firteen, fouhteen, fifteen, sisteen, (which was then followed by fouhteen, twenty!). I know we sometimes count the steps outside the house as we go up and down (there are 17), but I'd never heard him count these numbers, and in the correct order no less.