The same way every body else with 8 or more kids. Look at the table for 12 family. The dad works and the mom stays home. How do they do it?
I don't know about the Table for 12 family, but I think there have people on this thread who live in their area .. I think, until the show, they've survived on his job and donations?
other examples? The Duggars. Until they got to child 13, 14, 15 (? not sure ?) ... they got by without a TV show. Dad is very financially savvy, and they're debt free.
The McCaugheys? I know they reaped the benefits of an unusual birth early on, but I don't think they even did a yearly update this year. I'm not sure, but I think only dad works.
I have a friend with 7 kids, they're spread out over several years .. but they've gotten by over the years, sometimes on one salary.