Do You Measure Up?

Hello mathletes,

Measurement.  What is? How do we do it? Why is it useful? All fantastic questions. I'm not even going to bother with a standard dictionary definition of measurement because, in the creation of our own learning, is there really a standard definition of anything? The operational definition I will create to help you understand this concept is "determining a value for a feature of something".  Vague enough for you? Good.  Now that your mind is open, we shall proceed.

Want to know how much you weigh? You could measure your weight in pounds.  You could measure your weight in kilograms. You could measure your weight in stones (God save the queen!). You could measure your weight in books or M&Ms.  All you need is a sufficiently large enough scale.

Want to know how tall you are? You could measure your height in centimetres or metres. You could measure your height in inches or feet. You could even measure your height in hands.

Want to know how far the distance to or from something is? You could measure in kilometres or miles. You could measure in car lengths. You could measure it in minutes. I think you get the picture.

A famous song about measurement? 

 

Measurement provides useful information about something and can be done in many ways. What is important about measurement is that the units of measurement should be uniform.  If you wanted to weigh yourself in books, you could say that your weight is the equivalent of 25 books. It would be most accurate if the books all weighed the same amount. Remember those thick, heavy dictionaries?...Remember dictionaries at all? If you combined books of various weights (dictionaries and paperbacks) you likely wouldn't weigh the same number of books each time.  Conversions can be made between unlike units (eg. pounds to kilograms) only if they are measuring the same thing. Differing units, however, cannot be combined. There is no such thing as kilopounds and pounds cannot be converted to minutes because one is measuring weight while the other is measuring time.

There are different types of measurement that we learned about in class and that the textbook readings discuss. Perimeter measures the distance around an object. Area measures the surface across an object. Volume measures the space within a three dimensional object. Weight measures the mass of an object. Regardless, for measurement to mean something to the person doing the measuring, they must be familiar with the units. If I told you that I weighed 16 stones (God save the queen!), would that mean as much to you if I said that I weighed 224 pounds? I don't by the way, just sayin'.

Having difficulty measuring the area of a cylinder? 

One of the most important uses of information provided by measurement is the ability to make comparisons. Assistive technology/accommodations (ladders or step stools) aside, if you needed someone to get something from a high shelf you couldn't reach, you would compare yourself to someone who was taller than you and ask them to reach the object for you. Congratulations, you've instinctively taught yourself about measurement.

Cylinders are really just rectangles after all, aren't they?

Being familiar with units of measurement allows us to estimate. We can look at someone and estimate that they are about 6 feet tall because we are familiar with this unit of length. We can estimate how long 10 minutes is because we are familiar with this unit of time. Estimation is not as accurate as strict measurement but can be used when it is not imperative or there is no way to exactly determine an exact measurement. Measurement tools like scales can be used to help determine an accurate measurement but, especially in the case of electronic measurement tools, it is important that those tools are calibrated so that they produce an accurate measurement.

Stay measurable, mathletes.