Welcome, teachermom!
Great to hear that you are making all the effort to create not only your own flash cards, but even a video!!
After you do that, it'd be great if you could make a Little Reader category out of it, including the video, and share it with the rest of us. I can see it being very popular (and getting you many many points!

). You'd probably need to compress it into .flv . If you need help in doing that, let us know!
Re sequence between reading and math, I don't think there is any. Many of us show both reading and math. You can do them at different times of the day, or during the same session, depending on your LO's attention span.