Where's Waldo?

If this isn't real-world math, I don't know what is.

http://www.slate.com/articles/arts/culturebox/2013/11/where_s_waldo_a_new_strategy_for_locating_the_missing_man_in_martin_hanford.html

I like what you can do with this around probability and area. It also makes me think about what kids hear/understand when they use and read the word "random." Do they think that Waldo is placed randomly? Why or why not? What would the pages look like if he were to be placed randomly?

I also like that it takes something that looks like it has little order, and uses math to help you see something you wouldn't otherwise be able to notice.

Really Long Tweets

This "What If" from xkcd seems like a simple proportional reasoning problem--and could totally stay that way--but actually turns into something way more complicated, particularly when you consider growth over time. 

A Math Major Talks about Fear

Would kids believe it if it came from this girl instead of me? 

Poor Pete Tries Data Visualization

http://wtfviz.net/

The title may not be school-appropriate, but the awful data representations are a goldmine of "What's wrong with this?" problems.

What's Number Are You?

http://www.bbc.co.uk/news/world-15391515

According to this website, of all the people living on Earth, I was the 4,611,347,584th person to be born. Can you figure out how old I am???

There are lots of other interesting mathematical things about this. First, just the fact that the population of the Earth increased by about 2.5 billion people in my lifetime--more than half of what it was when I was born--is just staggering. I know that large numbers are hard for kids to conceptualize (adults too! me (non-kid, non-adult) too!), but there's something in here that makes you say WOAH. Even if you put in a kid's birthday (I picked a random 15 year old), there were still about 1 billion people born in their lifetime.

Of course there's also interesting stuff with exponential growth, how we would calculate this number, and so on. I'm also interested in the statistic of how many people have been born on Earth since the beginning of time. This website gives an interesting summary of that calculation, including this video:

The World Bank has a shorter video on the same topic: 

I like the stat in this video that 7% of all the people who have ever lived are alive today. Holy smokes!

Record Setting Stupidity

http://recordsetter.com/

This is a proportional reasoning teacher's dream. All of those problems I've used about competitive eaters, giant foods, and other world records, here are videos to match! Those weird facts are already a good hook for kids, but reading about someone cramming hot dogs down their throat will never top actually seeing it.

Biggest Trig Warmup Ever

This looks so fun! What a way to get kids to think about the composition and decomposition of the "sweet 16" triangles on a unit circle. I haven't found many get-up-and-move-around activities that feel appropriate to high schoolers, so I love this. The materials prep isn't even that bad because you only need the two triangles.

Extra challenge for when you have more students in the class: throw in the angles an increments of 15degrees that aren't already part of the key unit circle angles. Really this is a physical variation on the question of how many angles you can build from just from a set of drafting triangles.