1) The counting of the Bnei Yisroel from age 20 yrs.& up.
2) The counting of the Leviyim from age 30 days & up.
At the counting of the Bnei Yisrael it says “L’gulgelosom (counting of their heads).
At the counting of the Leviyim there is no mention of L’gulgelosom.
The Shu”t Chasam Sofer (Y.D. 294) quotes the Sefer Kol Yehuda in the name of R. Shmuel Krakover.
Had it have said at the Leviyim to count the heads, we might have thought that someone who was born with two heads should be counted as two.
Therefore no mention of heads. A two headed child is a single person and counted as one..
At the Bnei Yisrael’s counting, such a mistake could not have been made because a two headed person cannot survive for 20 years. Therefore the Torah could mention L’gulgelosom -to count the heads.
R. Menachem Azaryo from Fano (Asarah Ma’amoros) says the reason the Torah mentions L’gulgelosom, is because Moshe looked on the person’s head to see if he will produce
600,000 descendants .
If yes, this person became a Rosh Mishpacha. Moshe also checked how many Gilgulim this person will have to go through
