Lamed = 30, ordinal 12, reduced 3, no final form. Spelled in full, למד = 30+40+4 = 74.
Meaning
Lamed is 'goad', the ox-goad that drives the animal, and it is the only letter that ascends above the line of the script — the tradition reads that as the letter of learning (lilmod) reaching upward. Its 30 is the number of the days of the month and of the shekel, and on the tree it is the path of Justice between Geburah and Tiphareth.