Dividing unequal parts as equaly as possible
The original number of frames you have is 4955 frames and every student should receive as close to equal amount of frames as possible, the following is a solution I would suggest:

4955 frames / 20 students = 247.75

we take 247 (floor) and 248 (ceiling) as the possible number of frames that each student can get, now to figure out how many of those students should get 248 (the rest will get 247):

4955 mod 20 = 15

15 students will receive 248 frames and 5 will receive 247 frames

This works because .75 is 15/20 which therefore means 15 out of 20 got the ceiling value of the original division and the rest got the floor to equalise to .75