Adler-n-Subtract.com

Questions & AnswersProductsAbout Mitch Adler

Question

Dear Mitch,

I'm sure that math teachers get tired of hearing kids ask, "When are we ever going to use this in real life?" (Even I kind of get annoyed when kids keep asking it, even though I do like it when the teacher takes the time to answer it.) I know from listening to adults talk that even though a lot of college math isn't something you use in every day life unless you have an engineering job, or maybe architecture, and probably other kinds of jobs, I've also heard them say that a lot of high school math really does come in handy in real life. I heard that it's true for even some of the math we do in school that you would almost bet money has to be totally useless. Anyway, I was just wondering when would any really normal person in the real world need to know anything about absolute values?

Answer

Oh, good question. Believe it or not, having a little understanding of absolute values can help you a LOT in the "real world". I could give you a hundred examples, but instead I'll give you two hundred. ONLY KIDDING.

Actually, I think I can convince you with just one real example.

Drills and drill bits.

Many companies make drills. Many companies make drill bits, and most drill bits fit most drills. (Which is one of the many nice things the tool companies do for people). And when you buy drill bits (if you ever do) you will notice that they come in a wide range of sizes, which is the measurement of their diameter, and the difference between one diameter and the next is often so slight that it is difficult to tell by just looking at the bit; so, they each have numbers stamped on them (which are often too small to read, but I guess they figure it's the thought that counts.)

Now, no one is perfect, and no product is perfectly constructed every time. So, drill bits, like most things, expand and shrink with changes in temperatures, but they must still be close enough to make the right-sized hole for the particular screw that is to be turned within, and for accuracy, the metal bit must be close enough to exact to fit into the drill when everything is adjusted according to instructions. Any particular drill bit can be a drop too thick, or a drop too thin, but that's all the inaccuracy that the machine can tolerate and still make holes close to the ideal measurement for a screw to enter and stay in place with an appropriately snug fit – but the fit is too snug, the screwdriver is likely to strip the head of the screw getting it all the way down into place.

NOW: The direction of the inaccuracy of each drill bit does not matter – it can be a drop thicker than the perfect measurement, or a drop thinner – because the thing that determines if the parts will work together is the DIFFERENCE between the size the drill bit happens to be at that moment and the size the bit would be if everything in the world was exact and the temperature never changed, OR if the world was designed so that when the temperature changed it had no effect on anything else – and here I mean no effect on the thickness of the metal that forms the drill bit. The amount of the temperature-change's impact on the drill bit's size is a distance, or absolute value. But the magnitude (amount) of the inaccuracy does matter, as there is only so much a metal piece can be shoved into an imperfectly matched opening. Metal, like just about everything else, can be stretched or compressed. But only a small amount. And that amount is a distance, or how far away it is from the ideal measurement (+ or - ), or an absolute value.

And that's the real world!

ABSOLUTELY!

I hope this had some VALUE to you.

Thanks for writing in,

--Mitch