Cantrill: Right. People are able to retain a seven-digit phone number, but it drops off quickly at eight, nine, ten digits. // Whitney: If you're Cantonese, then it's ten. I have a very good friend, Roger Hui, who implements J. He was born in Hong Kong but grew up in Edmonton as I did. One day I asked him, "Roger, do you do math in English or Cantonese?" He smiled at me and said, "I do it in Cantonese because it's faster and it's completely regular."