1 km = 1000 m so 0.042 km = 1000*0.042 = 42 m. Simple!
there are 2,500 meters in 2.5 kilometers and 5,000 meters in 5 kilometers.
49 kilometers = 49,000 meters
13 kilometers = 13,000 meters
There is 0.005 kilometers in 5 meters.
16,000 meters is 16 kilometers.