## perspective ?, breaking a block up into sixths

im going through loomis's 'successful drawing' and i have a question. on page 37 of the book titled "blocks of specified dimensions' he breaks up blocks into sixths and he talks about practicing doing this until you can do it so thats what im trying to do. i cant figure out how he breaks up the length of the block on the left into sixths. i understand how to break it up into 1/2s 1/4ths 1/8ths 1/16ths etc, but i dont know the method of how to break it up into 3rds or 6ths and he doesnt really explain how he does it. the only way i can think of is to build the block, break it into two halves and then build another half underneath it and then break all those halves into more halves to get the whole thing broken down into 6ths. but im not sure if this is like inefficient or whatever and maybe theres a quicker solution to breaking it down into 6ths right from the start rather than something kind of roundabout.

edit: also, now im looking at the block on the right. is that supposed to be in two point perspective even though he sets it up like its one point (with there eventually being 3 all together?)?