symbologyBibleNumbers

Thus it allows for a lot of manipulations and hence
interpretations whether permissible or intended.
Exceptions to Hebrew Number Formation
There are exceptions. Numbers ending in 15 or 16 would be
written as yud-he (10+5) and yud-vav (10+6) (YH), since
the letters "yud he vav he" (YHWH) is the name of God YH is
also the name often used. Hence by convention, for the sake
of sanctity they are written as tet-vav (9+6 ) טו and
tet-zayin (9+7) טז are always used. The number 18
‏,יח yud-het, uses the same letters as the word for life het-yud
‏.חי So it is written
15 16 18
טו
9+6
Not
10+5
טז
9+7
Not
10+6
חי
8+10