Suppose you are testing the buoyancy of different objects . study the table and choose object with the greatest buoyant force

The formula to calculate buoyant force (FB) states that the upward force exerted on an immersed object is equal to the density (ρ ) of the fluid multiplied by both the fluid’s displaced volume (V) and the gravitational acceleration (g), or
FB = ρ x V x g. 
I hope that helped with what you're doing. 
You can also try water displacement in a graduated cylinder.

10.063g / 10.00 ml = 1.0063 g/ml which rounds off to 4 sig figs as: 1.006 g/ml