Taking measurements is an important part of scientific investigation. Scientific knowledge also gives us important information about taking measurements in our everyday lives. For example in this chapter we learned about scientific ways to measure our body temperature. In this case scientific research has discovered what our body temperature should be. Questions 1. Think of other ways that you use measurements in your everyday life. How has scientific research helped us to understand the importance of these measurements?
2. Identify some measurements where accuracy is important, and some measurements where precision is not that important.
Chapter Summary
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The International System of Units, the SI system, is the most widely used system of measurement. The SI system allows scientists throughout the world to communicate effectively about the data from their research. Length is a measurement of distance. The SI unit of length is the metre (m). Mass is the measurement of the amount of matter. The SI unit of mass is the kilogram (kg). The SI unit of time is the second (s). Temperature is a measure of how hot something is. It can be measured in degrees Celsius or in Kelvin. The SI unit of temperature is the Kelvin. Area is a measure of the size of the surface of an object. Volume is a measure of how much space something takes up. In deciding if a value is correct we must consider the accuracy and precision of the measurements. Accuracy is how close a measured value is to the actual, or true, value. Precision is how close the measured values are to each other.
