So I took 5,280 + 5,280 = 10,560 so now I can just take Ms. Smith's 8,305 and subtract it from 10,560 which gave me 2,255 so Mr. Roberts runs 2,255 more feet then Ms. Smith.
The last step you need to do is 5.25+0.03, because you took away 0.03 more than what the question asked so you need to add the 0.03 back, which gets you the final result of 5.28.