You're missing units! To calculate density, we need to know the units for both mass and volume.

Here's the formula for density:

Density = Mass / Volume

Let's assume:

* Mass = 40.0 grams (g)

* Volume = 80.0 cubic centimeters (cm³)

Now we can calculate:

Density = 40.0 g / 80.0 cm³ = 0.5 g/cm³

Therefore, the density of the object is 0.5 grams per cubic centimeter.