Arrange the following lengths in their increasing magnitude:

1 metre, 1 centimetre, 1 kilometre, 1 millimetre

1 cm = 10 mm

1 m = 100 cm = 1000 mm

Again, 1 km = 1000 m = 100000 cm = 10000000 mm.

Hence, 1 mm is smaller than 1 cm, 1 cm is smaller than 1 m, and 1 m is smaller than 1 km, i.e.,