Câu 1. Số ?

1km = ..hm                        1m = …dm           

1km =…m                         1 m =…cm

1 hm =…dam                    1 m = ..mm

1hm =…m                         1 dm =…cm

1 dam =…m                      1 cm =…mm.

Giải:

1km = 10 hm                        1m = 10 dm           

1km =1000 m                       1 m =100 cm

1 hm =10 dam                      1 m = 1000 mm

1hm =100 m                         1 dm =10 cm

1 dam =10 m                        1 cm =10 mm.