When Will I Ever Use This?


13
Nov 09

With out math, you can’t even…tie your shoes?

laces

I found I neat post on a new combinatorics proof that shows which manner of lacing shoes is the strongest. I came upon it via a great site called makezine.com. The constructionists would definitely approve.

pic by and within…


3
Nov 09

My question is…

math question-crop
I asked my math for liberal arts class what question they wished math could answer. I thought the results were extremely interesting. I got a number of personal economic questions.

how do I know if I have enough money to quit my job and for how long do I have to be unemployed for before I need more money?

i have been offered two different jobs. one has much less pay than the other but the benefits are great and has a pension. the second job has much better pay but has very bad benefits and no pension. which one should i take?

Which should I save for first? My kids college or my retirement? And how much do I need for both?

There was the academic.

what is the lowest grade i can get in my final on bio and still pass with a minimum of a 90, when i have received a 97 on my first test and a 98 on and i still have two left before the final…. not sure if this is a good one but its all i could think about the past few days.

One from the transportation sector.

My question is which lane is the best to get in when stuck in traffic. When I have to go straight and both the left and right lane can go straight. Will it be best to get in the left lane when a car may have to wait a while to turn left or get in the right lane when a car may have to turn right. Which lane is quicker if I have to continue straight?

And you could tell the holidays are coming.

What size turkey do you purchase for 12 people?
How long does a turkey of that size need to be in the oven and at what temperature?
What time would I need to start it for it to be done at 5pm?
How much will the tip cost when I miscalculate, ruin dinner, and need to order pizza? ;-)

Here was my favorite. Truly weird enough to be my own.

How far from the wall and how far from the person walking in the opposite direction do I walk in a hallway?

pic by A.v.L


7
Oct 09

The Twitter Ratio

twitter logo
To follow or not to follow? I found a nice post on Tech Crunch that argues people are implicitly using ratios all the time to help make that decision.

pic by mfilej


17
Jul 09

A Mathematician Goes on Vacation 6

floor -1I don’t get too many complaints about the uselessness of negative numbers, but every once in a while in a Prealgebra class somebody will claim that they’re never used in the real world. Above is the photographic evidence from within an elevator in Nikola Tesla Airport (Belgrade, Serbia) that negative integers are indeed used. And if one is ever in such an elevator, one surely thinks fondly (for once) of their math teacher. For how else would we know where to go?


10
Jul 09

When Will I Ever Use This?

wind machineI actually found a reference to variation that isn’t in a text book. The Wired Science blog had a post on high-altitude wind generation (pretty interesting in its own right). They describe the relationship between wind speed and power generated like this…

Wind’s power — energy which can be used to do work like spinning magnets to generate electricity — varies with the cube of its speed.

I wonder how many of the students I tortured with variation would remember what it means if they read this article? Those are the questions that keep a math teacher up at night. BTW, if you’re teaching variation. I’ve always found that students like knowing the world’s most famous equation e=mc^2 is a direct variation equation.