73 is soixante treize and is just this : a word (ok, two) one learns by heart. No French think that this is 60+13, but just 73. I understand the point about lo

73 is soixante treize and is just this : a word (ok, two) one learns by heart. No French think that this is 60+13, but just 73. I understand the point about logics in counting, but this is just a new word to learn, like déposition or balafré. One can analyze these words from an ethymology perspective but normally you just learn them by heart. At least this is what I do in English when I need to remember went or throughout .