500 m
First you need to convert 4.1 km into meters.
1 kilometer (kilo=1000) equals 1000 meters, so to convert 4.1 kilometers into meters you need to multiply 4.1 x 1000
4.1 x 1000 = 4,100
4.1 km = 4,100 m
To find out how many more meters art walked than Bill, you need to subtract the amount of meters Bill walked (3600 m) from the amount of meters Art walked (4100 m).
4,100 - 3,600 = 500
Art walked 500 more meters than Bill