Calculate that Grade, Dummies!

Hill slope and gradient

The worst of the vast crop of self-appointed "freelancer writers" who populated the internet in those heady pre-Panda days seem to have developed a nearly foolproof system: they would pick some topic and milk it for all it was worth. It obviously made no difference to them (or to their favorite websites) whether they knew anything about the topic in question, all that was important was that they could make some money; and eHow.com helped both ways. Occasional contributor to the mother lode of internet misinformation Mark Kennan (who sometimes calls himself Michael Keenan) did just that: he found multiple titles about maps, and grabbed them all. First, he did a piss-poor job of explaining map scales, then he took his lack of expertise with "How to Calculate the Grade of a Slope."¹

As so often happened in the Demand Media world, Mark got hung up with fitting his answer into a predetermined format (introduction plus 3 to 5 steps) and meeting a minimum word count, As a result, he had to pad his answer beyond the simple formula "gradient = 100 * (rise / run)"; and there's where he got himself into trouble.

First, according to Mark, the "tools" one needs for this process are

• Ruler or measuring tape
• Level, if needed
• Calculator

We can see where we might need the calculator (does no one do long division by hand any more?) and -- maybe, just maybe -- the measuring device, but a level? Why? Let's see what he says are the necessary steps. First, we need to "Calculate the rise by subtracting the starting elevation from the ending elevation. If it is a downhill section, this number should be negative. If it is an uphill, this number should be positive." OK, well, that's fine. Except, we wondered, which one of our tools would one use to find those elevations? And then, next, we need to "Calculate the run. Measure the horizontal distance between the starting and ending points. A level can help you measure horizontal distance."

Yep, he's right on the definition: the distance between start and end is the run... but how on earth do we use a level to measure horizontal distance? Do we turn it end over end like MIT students measuring the Charles River bridge in Smoots? If so, what's the conversion factor between "levels" and whatever the units of elevation may be? Dumbass... Mark completes the exercise by needing 56 words to express the thought "calculate 100 * (rise / run)"; in the process muddying the waters by proclaiming that

"If [the slope] is downhill, it will be negative. If it is uphill it will be positive...."

...which prompts us to ask (though it doesn't "beg the question," grammar idiots), "Is there any place where a slope only runs one way?"

Nope, Mark -- like so many of his eHow compatriots -- had no idea what he was talking about and decided to bullshit his way through it anyway. Some moronic content editor didn't help matters, either, but we don't know who he or she was. so Kennan need not share his Dumbass of the Day award.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was   https://sciencing.com/calculate-grade-slope-5135843.html

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