The physical education teacher in physical education class gave 60 students numbers 1 to 60. Students with four times the serial number stand back and let them go to five.

The first turn: the multiple of 4 is 60÷4= 15 (one). At this time, 15 people have their backs to the teacher; The second turn: the multiple of 5 is 60÷5= 12 (one), among which three people, 20, 40 and 60, who have the same multiple as 4, turned their backs to the teacher at the first turn, and now the three of them are facing the teacher again; When it is called a multiple of 5, only 9 people turn their backs on the teacher and 3 people face the teacher; At this time, 15+9-3=2 1 people turn their backs on the teacher; The third turn: the multiple of 6 is 60÷6= 10 (pieces), in which 12, 24, 36, 48 turned back to the teacher for the first time and now turned to the teacher; Turn your back on the teacher at the second turn and now face the teacher; Others turn their backs on the teacher (60 turn their backs on the teacher for the second time and the teacher for the third time). At this time, five people turned and left the teacher. At this time, 2 1+5-5 = 2 1 people turned and left the teacher. 60-2 1=39 (person); A: At present, there are 39 students facing teachers. So the answer is: 39.