How many do you think will hatch?

In total I have currently 54 eggs in incubators, 42 in this incubator and then 12 in my other one all from my own chickens, 10 in my 12 egg incubator are developing I had to get rid of two but I replaced them with eggs that are due to hatch the same day as these, so when the time comes for the other eggs to hatch I'll just move those two over into this incubator and manually turn them into my other incubator is free again, I have candled two eggs in the incubator in the picture and they are developing, so with that knowledge how many do you think will hatch? And also what do you think of my attempt at adding an extra egg? It's actually working pretty well