Yep! ANYTHING math-related you do can be counted, even if you're NOT reviewing.
Just remember when you're going through the lessons to exit out of them before you hit that "end of lesson quiz" section.
When my girls got that far ahead, we'd take a day off to bake! Cookies, making hard candies, a cake, even using those cool chocolate molds. In k12, it all counts. You're measuring ingredients (which is part of math) - you measure wrong, it doesn't turn out right! - so if it takes you half an hour to measure out all of your ingredients, count that 30 minutes towards your daily math time! You can do this with ANY recipe, of course, but cookies and such make for a great after school treat once you're done for the day and they've cooled down so you can frost them.
The same goes for any subject. If you're ahead in, say, History, and you have a History museum near your home, go to it! Count that hour (or two) you spend there towards your History time. Watch a lot of shows on the History channel? It counts!
Ahead in Science? Visit a local science museum. Watch a couple episodes of "How It's Made" or "Mythbusters", or any of the other hundreds of science-related shows. Count that half hour show as 30 minutes for the day...that hour long show (or 2 half hour shows) gets your 60 minutes for the day.
For Language Arts, you can count time spent reading your favorite book or a magazine...writing a letter to a friend (a hand-written one OR an email), be sure to double-check your grammar, spelling and punctuation (it doesn't have to actually be sent to count, either)....etc.
We always try to look for "double points" - or triple - whenever we could find them. A trip to the zoo is always a big score. How many animals does the zoo have? How many did you see? Use those numbers....what percentage of the animals did you see? There's some math. Study the signs by the animals. Where are they from? What do they eat? Etc. There's a bit of science. Is there any mention about the history of a particular animal? Such as when it was discovered, has it evolved over the years, if so, how has it evolved? A bit more science...AND History to boot. When you get home, pick your favorite animal that you saw that day, look around online, and write a short (3-5 paragraph) report - just make sure your Learning Coach checks it over for he spelling, grammar and punctuation if you're below high school level....if you are at the high school level, you can double-check it yourself. Anyway, there's some Language Arts for the day.
As long as your work is done - properly - you WILL end up with not enough hours. Public schools are based on hours (not how many days you attended), so it's always good to have that little extra time to call back on. When my daughter was in 2nd grade, I did the math. 920 hours are needed for the school year...with all of her classes PLUS the 36 minimum hours of P.E.? She would have only gotten around 875 hours...so...yeah...those "extra" hours are NEEDED to move to the next grade level...and they add up pretty quickly even if you're only doing 15 or 20 minutes extra a couple times a week.