My daughter went from a 720 to an 800 on the math on the Aug 26, 2017 SAT, by only doing practice tests. We are both wondering whether there was an error. Anybody else surprised - either pos or neg about their Aug scores? We are worried that there was some kind of glitch in the scoring - although a good one 
I hope there wasn’t an error! My son’s math score went up 50 points (so did his superscore). We were thrilled. He did do plenty of review.
My Ds math went up 100 points but she studied all summer for it. She only did practice tests and then reviewed errors. I think with the math section as explained to me…kids who have advanced early in math (my D had AP calc as a junior) are pretty far away from their Alg 1, 2 and Geometry classes which is the bulk of the math section. They just need to review. Congrats! We had a very happy morning at my house!