Hey there. I don't know how to to this problem either, but I'd suggest searching up the formula for volume or whatever. Just enter the values that are in the first sentence of the question, and then divide the sum by 1/2 to see how many times 1/2 [cubes] would go into the shape.
Also, sorry that you're having a tough time. It sucks to have irresponsible parents, I know that too, but just try your hardest. Remembering that there are people who are facing the same things that you are might help, because if they're trying their best, then so should you. So, let's all do our best and try to push through hard times, whether we've been facing the same problems for years and years, or if something just ruins our day. Keep on fighting, and I hope this helped you somewhat.
