Why are measurements approximations

For example, if you are using a ruler with centimetre and half-centimetre divisions as you might find on a metre stick , you can only approximate the measurement to the nearest mm 0.

If using a micrometer, it is possible to be as precise as 0. Why are measurements approximations? Physics Introduction to Physics Measurement and Units. Apr 19, If using a laser, it is possible to be as precise to the level of the nanometre, if not smaller. Ask Question. Asked 4 years, 1 month ago. Active 4 years, 1 month ago. Viewed 94 times.

Improve this question. Remy Remy 7 7 bronze badges. Add a comment. Active Oldest Votes. Improve this answer. Sign up or log in Sign up using Google. Sign up using Facebook. This is because people always think that precision translates into accuracy, and that when a value is approximate, you are making it more precise and thus accurate. Things might have started to get a bit confusing here, so now it will be good to define both terms.

So what is the difference between precision and approximation? Precision is the proximity of a set of obtained results to each other. So what does this definition of precision say? To begin with, precision is not synonymous with accuracy.

A set of values might be precise, that is, very close to each other, and not accurate. Accuracy is the closeness of a value to a given true value. For example, during the course of a titration experiment, you performed four tests of the same sample and obtained These results are proximal and hence precise, but when you calculated, you obtained an actual result of Precision might also mean giving an exact or more distinct detail about something, a measurement for example.

Measuring in millimetres gives a more precise result than in centimetres, just as taking measurements using a digital scale gives a much more distinct value than the analogue ones. Being precise in this sense might however lead to accuracy. Approximation simply means making a value with fewer digits or making the value simpler. When you round a number, you are making it shorter hence closer to the initial value.

Now we can see that approximation is different from precision. From the definition of approximation and precision, we can make a comparison table to make their differences clearer.