Jump to content

Menu

rise over run


Recommended Posts

What are your tricks to rise over run?

 

Understanding that a slope of a hill is literally the vertical gain in height per horizontal distance.

A slope of zero means the road is flat (zero gain in height, no matter how far you travel horizontally)

 

I would not find it particularly useful to teach my kids a mnemonic if they did not have a conceptual understanding of "slope".

Link to comment
Share on other sites

Regentrude: that still doesn;t make sense to me. I know what a slope is which is how steep a line is. But why would you put the rise on top of the run.

 

because "how steep" is precisely the ratio of the vertical gain per horizontal distance, in other words the fraction (horizontal gain)/(vertical distance) or, colloquially speaking, rise over run.

Large slope means large vertical gain over a small horizontal distance.

Zero slope means no vertical gain - so clearly the vertical must be on top of the fraction.

Link to comment
Share on other sites

Thoughts from a very visual and kinesthetic learner:

 

With slope, think how much higher or lower (or how flat) a path gets as you keep walking forward. So if you are hiking, the terrain is hilly, you are climbing more (rise) than you are walking or running forwards (run). The distance that you went upwards (y axis or rise) is more than the distance that you went forward (x axis or run). You are looking at how much rise is increasing compared to run. With that hilly terrain, rise is greater than run, and you get a higher ratio (because it's steeper than a flat terrain and you are going up a hill, not down or flat). It wouldn't make sense to say that it's less steep (because that's what run over rise will give you) when you know and can see for yourself that it's a very hilly, steep terrain.

 

Now just transfer that to a 2-dimensional drawing...y-axis showing rise, x-axis showing run and the diagonal line is your journey up the hill.

 

What happens when you go downhill instead of uphill? (we like reverse engineering and thinking from a different angle...helps concepts stick better!)

 

Apart from asking here, you can also consult Better Explained, Math Forum and Purple Math.

I felt that for slope, math forum's explanation was clearer: http://mathforum.org/library/drmath/view/66624.html

HTH!

Link to comment
Share on other sites

Rise is the change going "up" or "down" - think about the sunrise in the morning. The Y axis goes "up" and "down" (so to speak, like the sun) Although this isn't technically true, the kids can relate, kwim.

You Run along the flat ground - the X-axis is flat "like the ground"

 

RISE

_____

 

RUN

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...