a)

1 cm² = 100 mm²

 

$5{\text{cm}}^2=500{\text{mm}}^2$                          $31{\text{cm}}^2=3100{\text{mm}}^2$  

 

b)

1 dm² = 100 cm²  = 10000 mm²

$3{\text{dm}}^2=30000{\text{mm}}^2$                           $25{\text{dm}}^2=250000{\text{mm}}^2$   

 

c)

1 dm² = 100 cm²

 

$7{\text{dm}}^2=700{\text{cm}}^2$                             $50{\text{dm}}^2=5000{\text{cm}}^2$   

 

d)

1 cm² = 100 mm²

0,01 cm² = 1 mm²

$4300{\text{mm}}^2=43{\text{cm}}^2$                       $19000{\text{mm}}^2=190{\text{cm}}^2$  

 

e)

1 dm² = 10000 mm²

0,0001 dm² = 1 mm²

$20000{\text{mm}}^2=2{\text{dm}}^2$                        $180000{\text{mm}}^2=18{\text{dm}}^2$   

 

f)

1 dm² = 100 cm²

0,01 dm² = 1 cm²

$2300{\text{cm}}^2=23{\text{dm}}^2$                         $111000{\text{cm}}^2=1110{\text{dm}}^2$