It truly doesn't matter which you measure first. Unless you are trying to find a property of something that is dependent on either mass or volume, but not the other; in which case you would find first the one you need to make the unknown property.
mass
The same way you measure the density of any other material. Divide the mass of a sample by its volume.
To find the density of a liquid, you need to measure its mass and volume. The formula for density is density mass/volume. First, measure the mass of the liquid using a scale. Then, measure the volume of the liquid using a graduated cylinder. Finally, divide the mass by the volume to calculate the density of the liquid.
mass, then you can see how much space it takes up
You can dip the irregular solid in a water or other suitable liquid. This is how, you can measure the volume of the solid. The mass can be measured by weighing scale. Mass/volume = density. It is easy to measure the mass and volume of the liquid. First measure the mass the container. Then add the liquid to it. You will get the mass of the liquid. Then measure the volume of the liquid. Use the above formula to calculate the density of the liquid.
mass/volume = density
-- Measure its mass. -- Measure its volume. -- Divide its mass by its volume. The result is its density.
Density = mass/volume.
You MEASURE mass with a balance. You MEASURE volume (if liquid) with a graduated cylinder. Then take these and divide. density = mass divided by volume.
To find the density of an object, you need to measure its mass (using a scale) and its volume (using a ruler, displacement method, or geometric calculations). Density is calculated by dividing the mass of an object by its volume.
The density of a substance is the ratio of its mass to its volume. So, I would measure the mass and volume of a substance to calculate density.
To calculate the density of an irregular shaped object like a key, you would first measure its mass using a scale. Next, you would measure its volume using a displacement method with water. Finally, you would divide the mass of the key by its volume to determine the density.