Tuesday, November 24, 2009

"I don't use fractions in my daily life" ... Really?!

1/2 by Leo Reynolds, on Flickr
Creative Commons Attribution-Noncommercial-Share Alike 2.0 Generic License by Leo Reynolds

In a recent discussion about fractions in one of my online math courses, a student claimed s/he does not use fractions in her/his daily life but only in math courses. This student's response was a precious "teaching moment" to promote math awareness of how math is embedded in our lives. Below, you will find my reply to this student's post:

Thank you for your response, though I may have to respectfully disagree with
your assessment that you do not use fractions in your daily life. We are
constantly working with portions or making decisions out of a set of choices
in our daily lives, which is the same as working with fractions. Here are a
few examples:

-- When pouring milk, juice, or soda in a cup, we are using a portion (fraction!) of the milk, juice, or soda available in the container.
-- When we receive our paycheck, a part (fraction!) of our money is used to pay the bills.
-- When we stop at an intersection and decide to make a left turn, your decision
(fraction!) was based on 4 posibilities: go straight, turn left, turn right, or go back (U-turn).
-- When we go shopping and take advantage of the sale of 25% off (fraction!) on every item.
-- When we type our name in the computer, we only use a few keys (fraction!) of the
keyboard.
-- When we have a headache, we take 1 or 2 Tylenol tablets (fraction!) out of the bottle.

These are only a few examples. There will be many more in this discussion, which I hope it will help you gain awareness that we all use fractions (and math!) every day in our lives.

I hope this helps.


Help me add more examples to this list, so I can share them with my students.

No "Wiggle" in Rowing!

I recently read this interesting article of how math was used to solve an issue that rowing athletes often need to overcome during races: "the wiggling boat." Once again, Math is in places that you least expect! Read this interesting article from "Technology Review" by clicking the link below. Enjoy!
Mathematician Solves Rowing Boat "Wiggle" Problem
A mathematician has discovered two entirely new arrangements of rowers in a racing eight in which the rowing forces cancel to make the boat wiggle-free.

The placement of the rowers, the "rig" of the boat, obviously has consequences for the motion of the boat. The question is how best to arrange an even number of crew members in a coxless racing boat in a way that minimizes or eliminates wiggle.

The traditional way of rigging a boat places rowers alternately pulling oars on each side of the boat. "The traditional rig appears symmetrical and simple in ways that might tempt you into thinking it is in every sense optimal. However, this is not the case," says Barrow who goes on to show that the balance of forces in this rig as the oars are pulled through the water always produces a wiggle.

What's the betting that that we'll see at least one of the new rigs at the 2012 Olympics in London?

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