While many scientific concepts and formulas are immensely complicated, they all rely on a single concept: accurate measurement. With the development of precise measuring instruments, scientists have been able to standardize a range of processes and formulas to advance the discipline. Precise, standardized measurement is truly the glue that holds scientific inquiry together. It isn't difficult describing the importance of measuring instruments to a classroom or audience. All you need to do is use a few basic measuring instruments and explain their importance.
Lay out your measuring instruments on a table and describe to your class or audience the purpose of each one.
Explain that, in scientific inquiry, our eyes cannot always provide an accurate measurement, so tools are needed.
Direct students or an audience to do some research on times before scientific measurement became prevalent, or describe your own research into the subject. Conduct a discussion about the limitations of non-standard forms of measurement.
Draw students' attention to the exact measurements on each instrument and the units of measurement displayed. Use the measuring instruments several times to take measurements. Ask students if they can pinpoint any obvious flaws in the use of measuring instruments. Explain that problems can arise if there is no agreement on what each unit of measurement represents.
Conclude your talk with a description of universal measurements. These measurements set the worldwide standard for our units of measurement. They ensure that a kilometer in one country represents the same distance in another. Tie this into the concept of measuring instruments to hammer home for students the exact precision of measuring instruments over your senses.