Hi i have read a few threads now and jst want someone to explain the numbers realting to gearing

. I am looking at buying a brushless motor (6.5t - 9.5t0 and want to know what the numbers people are putting down like 23/80 and how to get a good speed whilst keeping the acceleration highish.
i have only raced at one track where the main straight wasnt very long and was getting demolished midway through it, any help would be much appreciated