đổi :
5cm2=.......mm2
12km2=.....hm2
1hm2= ..........m2
7hm2=.............m2
1m2= .............cm2
5m2=.........cm2
12m29dm2=...........dm2
37dam24m2 = .............m2
800mm2 = ...............cm2
12000hm2=.................km2
150cm2=............dm2............cm2
3400dm2=............m2
90000m2=............hm2
2010m2=............dam2..........m2