Convert to standard notation 6.85 × 10^8

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Acarton of juice contains 64 ounces miss wilson bought six cartons of juice how many ounces of juice did she buy