To get the density, we divide mass over volume
density = mass/volume
density = (18 grams)/(2 cubic centimeters)
density = (18/2) grams per cubic cm
density = 9 grams per cubic cm
This means one unit block has 9 grams of this material. By "unit block", I mean 1 cm by 1 cm by 1 cm (volume = length*width*height = 1*1*1 =1)
