Decimetres-cubed seems like a very odd unit to me. Why not just call it a litre?

I can see the point in training students to be careful with units - perhaps they're deliberately trying to catch out students who aren't reading carefully enough. But if that were the case, I'd expect them to use different units in different questions.

How does the marking scheme work - do you just lose one mark for failing to get the units right, or lose all of the marks for not giving the right numerical answer?