Oh I see what you mean now, that is clearly 9cm, unless someone is producing wooden imperial measures marked out with tenth divisions
(
97800,
Thu 11 Oct 2018, 11:09,
archived)
it was a US school ruler.
(
JauntyArt,
Thu 11 Oct 2018, 11:15,
archived)
Like most US schoolkids' lives, it's cruelly and unnecessarily ended at 10 and a half
(
97800,
Thu 11 Oct 2018, 12:13,
archived)