1 cm = 10 mm

1 cm² = 100 mm²

 

1 ha = 100 a

 

1 m = 10 dm

1 m² = 100 dm²

 

1a = 100 m²

 

1 ha = 10 000 m²

 

1 km = 1000 m

1 km² = 1 000 000 m²

 

 

$\underline{45{\text{cm}}^2=4500{\text{mm}}^2}$  

 

$\underline{0,45\text{ha}=45\text{a}}$  

 

$\underline{0,45\text{a}=45{\text{m}}^2}$     

 

$\underline{4,5{\text{m}}^2=450{\text{dm}}^2}$  

 

$4,5{\text{km}}^2=4,5\cdot 1000000{\text{m}}^2=4500000{\text{m}}^2=4500000:10000\text{ha}=450\text{ha}$