A car wheel has a diameter of 0.4 meters.
Work out how many full turns the wheel makes when the car travels a kilometer
C = d pi
C = Circumference
d = diameter
C = d * pi
In this case:
C = 0.4 pi
C = 0.4 * 3.14 = 1.256 m
1 km = 1000 m
1000 / 1.256 = 796.17834395 turns
797 turns rounded for full turn