How long do you spend on a lesson? We've just been flying through Beta, and I'm a little concerned. We started it at the beginning of February, and we're now on Lesson 21 with Paul and Lesson 24 with Coleen. We don't move on until they've mastered the concept, but that's been happening with the first time the lesson is presented. Today is the first time they've both struggled with the concept, but its subtraction with regrouping and they're trying to subtract the wrong way.
So, should I slow down, even though they've mastered the topic at hand? We do several review pages a day, but maybe we should do more? I'm sure they'll slow down once we hit Gamma, but going so quickly through a year's worth of work is worrisome. Am I pushing too hard? I feel like we've finally gotten into a groove of learning, and I don't want to lose the momentum.
I'd love to hear your thoughts!

Don't worry about them going through it easily. That is the whole point. MUS teaches the child so they "get it". I have used MUS since DS was in K and we slowed down for maybe 2 lessons. It only takes ds 15-20minutes a day for the math book. We also do the online drill as well.

I know that DS has a solid understanding of Math concepts and he won't hesitate to tell you that it is his favorite subject.

We generally cover a lesson in 2-3 days....or 2 complete lessons per week. On Monday, we watch the video and do pages A-C. Then on Tuesday, we do pages D-F. On Wednesday, my oldest dd (DELTA book) does the test. If she does well, then we move on. We'll go ahead and watch the next lesson's video and do pages A-C. Then on Thursday pages D-F. On Friday, we'll do the test and some other supplemental math stuff from another program.

I think it's fine and there's no reason to slow them down unless they need more time to master a concept. We've been all around the block on this - for primer and the first few chapters of alpha we did 2 chapters a week, the last 2 weeks we were only able to do one chapter per week, but now this week we are back to 2 chapters.....so who knows. I say go at whatever pace fits and don't worry if you are flying through the book. :)