90 mm = (a)   cm

3 cm 4 mm = (a)   mm

7 dm = (a)   cm

5 dm 2 cm = (a)   cn

50 cm = (a)   dm

8 m = (a)   dm

3 m 6 dm = (a)   dm

2 m = (a)   cm

40 dm = (a)   m

2000 m = (a)   km

3 km = (a)   m

3 km 700 m = (a)   m