The video animation shows what is going on when you merge two lists together. You're comparing the first two indices and sorting them to complete that step.
Ahh, the autism registry they said they weren't going to put together just two weeks ago after they announced it and then faced backlash. It's back again already.
Teaching in k-12. It's very politicized right now, but I suspect they're low on bodies. It's a tough job, and in many areas, you should expect to be teaching something outside of your specialty.
https://en.m.wikipedia.org/wiki/Merge_sort
The video animation shows what is going on when you merge two lists together. You're comparing the first two indices and sorting them to complete that step.