Precise measurements of physical quantities are a need of science. For example, to ascertain the speed of an aircraft, one must have an accurate method to find its positions at closely separated instants of time. This was the actual motivation behind the discovery of radar in World War II. Think of different examples in modern science where precise measurements of length, time, mass etc. are needed. Also, wherever you can, give a quantitative idea of the precision needed.
It is true that the precise measurements of physical quantities is very essential for science. For instance, laser length measurements require a precision in the order of Angstrom (1 Å = 10–10 m). In satellite launching through space rockets, time is an important factor and is measured up to a precision of the order of 1 micro second (1μs = 10-6 s). Mass of sub-atomic particles are measured in the order of 10-30 kg. Inter-atomic spacing is measured in the order of a few Angstroms which needs to be precise to avoid errors in spectroscopy.