1 droplet of water is mathematically completely different than 2 droplets of water combined. 1+1 = 1+1 = 2. Instead of writing 1+1 again, and calling it 1+1 again, we invented a new word/symbol for that. We call that symbol "two". She doesn't realize that in her world, the "big droplet" is her new word/symbol for the two droplets added up. Big = 2, droplet = 1. She is kinda saying 2 = two ones "big" droplet = two droplets