Precision

Learning Objectives Define precision in the context of measurement. Distinguish between precision and accuracy in various scenarios. Identify the precision of a measurement based on the measuring tool used. Compare the precision of two or more different measurements. Explain why precision is important in real-world applications. Determine the appropriate level of precision needed for a given task. Express measurements with an appropriate level of precision. Have you ever wondered why some rulers have tiny lines and others only big ones? 📏 What difference do those little lines make when you're measuring something? In this lesson, we'll explore the concept of precision in measurement. You'll learn what precision means, how it's different from accuracy,...

TermDefinitionExample PrecisionPrecision refers to how close repeated measurements are to each other, or how detailed and fine a measurement can be. It's about the level of detail or the smallest unit a measuring tool can show.If you measure a pencil three times and get 15.3 cm, 15.2 cm, and 15.3 cm, your measurements are precise because they are very close to each other. The ruler used allows for measurements to the nearest millimeter (0.1 cm). AccuracyAccuracy refers to how close a measurement is to the true or actual value of what is being measured.If a pencil is actually 15.0 cm long, and your measurement is 15.3 cm, your measurement is not very accurate, even if it was precise (repeatedly 15.3 cm). Measuring ToolAn instrument used to quantify a physical quantity, such as length,...

Rule for Identifying Precision from a Tool The precision of a measurement is determined by the smallest unit or increment marked on the measuring tool. To find how precise a measurement can be, look at the smallest division on the instrument. For example, if a ruler has markings for every millimeter, it can measure to the nearest millimeter. Rule for Stating Measurement Precision A measurement should be recorded to the nearest smallest unit of the measuring tool, often including one estimated digit beyond the smallest marking if possible. When you read a measurement, you state it to the level of detail the tool allows. For Grade 7, this means recording to the smallest marked unit. For example, if a ruler has millimeter markings, a measurement should be recorded as 12.3 cm (t...