Density from area and volume worksheets

Density is how much of something sits in one unit of space, and finding it takes two steps: work out the area or the volume from the figure, then share the amount over it. These free printable worksheets draw the shape and give the amount; the size is the part a student finds.

Density from area and volume
Density from area and volume worksheet — Per square mile, per cubic cm, free printable with answer key

The answer key prints on a separate page.

What's on this sheet

Both of the standard's own examples are here. A rectangular piece of land with a population on it gives people per square mile — the number a census uses, and the reason two counties of different sizes can be compared at all. A rectangular block with a mass gives grams per cubic centimeter, which is the density of the MATERIAL: the same 11 g/cm³ whether the block of lead is small or large, and a student who notices that has understood what a rate per unit is for.

Why this sheet works

The reason it is a geometry sheet and not a rate sheet is the first step. The figure is labelled with its sides, not its size, so the area or volume has to be worked out before there is anything to divide. That is what modeling with geometry means: the shape carries the information, and reading it is part of the question.

How this one works

People per square mile

15 × 12=180 sq mi
3,600÷180=20
20 people per sq mi
  1. First the area of the land, because the question gives its sides and not its size: 15 × 12 = 180 square miles.
  2. Density is how much there is in ONE unit, so share the people over the area: 3,600 ÷ 180 = 20.
  3. So 20 people live on each square mile. That is the density — a count for one unit of area, which is why it can be compared between counties of different sizes.