Observations halfway through the video:
I got 5, but from the fact that 50 reversed is 5, 50 - 5 = 45
But anyways 5 was just like what Prof. Loh got
Coincidence? I THINK NOT
Also
Prof. Loh's guess and check numbers
74 - 47 = 27
84 - 48 = 36
92 - 29 = 63
83 - 38 = 45
All multiples of 9, and it seems that the higher number you start with, the higher your sum. It is just a general trend, of course, as you can see 84 - 48 was a lot lower than 83 - 38.
But...
Coincidence? I THINK NOT
And as it turns out... I thought right
Coincidence?