Humans shed about three million particles of skin every five hours. humans can shed about fifty thousand particles of skin every five minutes. the approximate number of particles of skin a human can shed in five hours can be written in the form a × 10b, where a is 3 and b the approximate number of particles of skin a human can shed in five minutes can be written in the form a × 10b, where a is 5 and b is humans shed approximately times more particles of skin in five hours than in five minutes.