Luis walked one-eighth of the distance to school. What part of distance to school does he still need to walk?

7/8 you subtract 1/8 from 8/8

Total Distance = x

Luis walked one-eighth of x = x (1/8) = x/8

He still need to walk = Total Distance - Distance covered

He still need to walk = x-x/8

He still need to walk = (8x-x) / 8

He still need to walk = 7x/8

He still need to walk = x (7/8)

He still need to walk seven-eighth of the total distance.