Dd8 has been done with her homeschool studies early nearly every day for the past few weeks, while dd10 struggles to get through with her work before lunch and the drive to their charter school. Dd10 doesn't have that many more subjects, and I let her do her grammar exercises verbally most days. I think dd10 spends so much longer on her work because math facts just don't come as easily to her as they do to dd8; she seems to spend a lot of time sighing while sitting over her open math book.
Over lunch today I asked her if she sits over her math sometimes without doing it, and dd10 replied that she often looks off into space. I have challenged her to change that habit so that she doesn't let herself stare into space until after she has finished the problem she is currently doing. A little mental down time is fine, but taking it in the middle of a problem makes it so she essentially starts the problem all over after her stare break.
Hopefully, she can make this small behavior change so that her math lesson doesn't fill all the available time in the morning.