Arrange the following lengths in their increasing magnitude:
1 meter, 1 centimeter, 1 kilometer, 1 millimeter.
1 kilometer (km) = 1000 meter (m)
1 meter (m) = 100 centimeter (cm)
1 centimeter (cm) = 10 millimeter (mm)
Hence, the ascending order of given unit is as follows:
1 millimeter < 1 centimeter < 1 meter < 1 kilometer.