If 1 mL = 0.001 dm3, then we have a given of 2330 mL to be converted to a dm3 unit; we can solve this by doing;
2330 mL x 0.001 dm3 / 1 mL = 2.33 dm3
Therefore, 2330 mL is equivalent to 2.33 dm3. This was solved by multiplying 2330 to 0.001 and cancelling out the mL units, then used dm3 unit as the problem required at first.