The equation for density is:

where the mass is in grams and the volume is in
.
We are given 4,000 kilograms, and we know that there are 1,000 grams in 1 kilogram, so we need to multiply to convert to grams:

We are also given 0.5
, and we need to convert to
. We know that there are 100 cm in 1 m, and since we are talking about cubic volume, we must also raise 100 to the 3rd power:
. So now we know that there are 1,000,000
in 1
. We need to then multiply 1,000,000 cm by 0.5 in order to find the volume that was given in the question:

So now that we have the correct units, let's plug them into the equation:


So now we know that the density is 8g/cubic centimeter.