Roberto wants to clean up his neighborhood by picking up trash. The total distance around his block is 1 3/4 of a mile. He decides to do this over a two-day period. If he walks 5/8 of a mile on the first day, how far does he need to walk the second day to pick up trash?(1

3/4 - 5/8) = 7/8 mile Answer: \boxed{\frac{7}{8}\text{ mile}}.