The formula for density is: #rho = m/V#

=> where #rho# is the density in either #kg/L# or the variant conversions - #g/mL#, etc, mass is the mass of the object in #kg# or other variants, and #V# is the volume in #L# or other variants.

Mass of an object can be measured in either #g# or #kg# by using a scale.

Volume of the object can either be calculated by #V=lwh# or through a water displacement experiment - getting a beaker of water and placing the object in the beaker. Subtract the new measure of water with the original measure. The difference is the volume of the object.

In the video, the density was found online, and the volume was found by subtracting the final volume of water #(425 mL)# by the initial volume #(150 mL)#, equaling #275 mL# - the volume of the object.

When calculating the mass (in the video), the mass will come out in grams because of the relationship between mass and volume. You can convert the variable to another, like #mL -> L#, but then your mass will be in #kg#.

Hope this helps :)