The following procedure will be performed using both  10 mL and 25 mL graduated cylinders.
   First measure the mass of each DRY graduated cylinder, as shown for the 10 mL cylinder on the right.  If the graduated cylinder is wet inside please use paper towels to dry it.  The paper towels are located above the lab benches.  Be sure to remember to record the mass on the data sheet.  The mass of this 10 mL graduated cylinder would be recorded as 25.964 g
Next, fill the cylinder with the liquid close to the top of the measuring scale without going over.  (NOTE:  the experiment done on this web page uses concentrated Sulfuric Acid, your experiment uses water).
Also DO NOT forget to record the precise volume of liquid in the graduated cylinder.  The cylinder to the right has a volume of 9.90 mL. (NOTE:  Because the smallest division on this graduated cylinder is 0.1 mL, we can measure to the nearest 0.05 mL and therefore the last zero in the measurement is significant.  Your graduated cylinder may not be as precise.)
Then take a mass of the filled cylinder on the balance.  Shown to the left is the mass of the cylinder full of liquid.  Be sure to record the value of your filled cylinder on your data sheet.
Next calculate the mass of the liquid in the cylinder by subtracting the mass of the empty graduated cylinder from the mass of the graduated cylinder filled with the liquid.

 mass of liquid in cylinder = 43.876 g  -  25.964 g  =  17.912 g  (for conc. sulfuric acid)

    After you have calculated the mass of the liquid, next calculate the density by dividing the mass of the liquid by the precise volume of the liquid in the graduated cylinder.

      density of liquid = 17.912 g /  9.90 mL  =   1.81 g/mL (for conc. sulfuric acid)

    The second trial using the 25 mL graduated cylinder (not shown on this page) had a density of 1.79 g/mL.  After both densities have been calculated for the 10 mL and 25 mL graduated cylinders, add these two numbers together and divide by 2, to get the average density.  (NOTE:  The zero is significant in this answer.)

    average density = (1.81 g/mL  +  1.79 g/mL) / 2  =  1.80 g/mL (for conc. sulfuric acid)