Réponse:

1)

- le mètre

- km2

- litre

2) km hm dam m dcm cm mm

3)

1km =100m

10 500 m = 10,5 km

325 cm = 3,25 m

1ha = 10000 m2

125 g = 0,125kg

3,5min = 210 sec

1m³ = 1000 L

1dm3 = 1L

1t = 1000 kg

1kg = 1000g

2,5h = 150min

1h = 3600sec