We were able to dual-enroll DS with the K12 and his regular public school. He was able to complete 5 years of math (through pre-Algebra B) in 2 years using their self-paced program during his classes math time. And since the K12 was through a public charter school, we didn't pay a dime; we had to get our principal sign off saying that they were willing to let him dual-enroll (which means less money for them). I'm not sure that every k12 program or bricks-and-mortar school are open to dual-enrolling, but this solution certainly saved our sanity (we could not cope with another year of incremental learning with Saxon!)