Measurement is the comparison of given physical quantity with the unknown standard quantity of the same nature. In this chapter, we get enlightened about the most fundamental topic in physics, measurements and experimentation. Physics is a natural science that deals with the nature, behaviour and properties of energy and matter. It requires experiential learning that involve experimentation. To gauge different physical quantities that we study in physics, a complete understanding of different units is essential. Unit is used to measure the magnitudes of different quantities of the same nature. Students are also enlightened with practical aspects of this unit such as the use of screw gauge and vernier callipers for measurement of various physical quantities such as the thickness of a wire, the radius of cylinders etc. The chapter also discusses time and simple pendulum and various numerical are also solved on the same topic. Towards the end of the explanation, numerical are solved, along with examples so that students understand the calculation and expression.