Piper Jaffray’s Gene Munster, who makes a living walking through AT&T (T) stores counting Apple (AAPL) iPhone sales says that the recent $200 price cut has increased unit sales by 300% from 9,000 a day to 27,000 a day.

According to Business 2.0, Munster thinks the improvement will move down to a sustained 50% increase. There is no way to confirm that number or tell whether it is close to accurate.

Apple will still have to do better than a 50% increase to offset the $200 price drop.

End of the math lesson.

Douglas A. McIntyre