When your changing kilometers to miles the formulate is divide the kilometers by 8 then take that answer an multiple by 5 that would give you the number of miles that you have left to travel. So, 100 kilometers divided by 8 equals 12.5. You multiple 12.5 by 5 and you get 62.5 miles. So from miles to kilometers you would take 62.5 miles divided by 5 equals 12.5 and multiple that by 8 and it equals 100 kilometers.