Final answer:
When measuring the volume of a liquid in a graduated cylinder, always read at the bottom of the meniscus for an accurate measurement. Estimations should be made to the nearest 0.1 mL.
Step-by-step explanation:
When reading the volume of a liquid against a graduation mark on a measuring device like a graduated cylinder, you should hold the device at eye level and read the mark at the bottom of the meniscus. This is the lowest point on the curved surface of the liquid, providing you with the most accurate measurement. For instance, if the bottom of the meniscus is between the 21 and 22 mL marks on the cylinder, you can mentally subdivide that space into tenths of a milliliter to estimate the liquid's volume.
Refer to an illustration such as Figure 1.26 to see the meniscus lying between two graduation marks. If it appears closer to the higher mark, you might estimate the volume as 21.6 mL, where 21.6 has the last digit as an estimate. Remember that it is not useful to estimate beyond one decimal place, as graduated cylinders generally allow for measurements to the nearest 0.1 mL.