Wednesday, September 23, 2015 is the Autumnal Equinox. It is the time of year when the imaginary plane that might pass through the Earth's Equator would also travel through the center of the Sun. At this auspicious moment the number of sunlight hours and night time hours are about the same all over the Earth and in the Northern Hemisphere we move into the Fall season.

# Oreo Stuffiness

There is yet another Oreo...

*ABC Breaking News*

This activity builds off the work that Dan Anderson's math class revealed about Original Oreos and Double Stuff Oreos. Students begin by working with the weight of just the Oreo wafer and the total weight of an Oreo cookie in order to determine the weight of the Oreo's "stuf" (the unknown). Is the Double Stuf actually double the stuff? Then students repeat the process with data from the new Oreo Thin. How "stufy" is the new Oreo Thin? Students consider the ratio of "stuf" to wafer in the Original Oreo, Double Stuff, Triple Stuf and Oreo Thin and rank the four from least to greatest in ratio of "stufiness".

# How much can my DVR record?

### How many hours of HD video can my DVR strore? How about SD video?

I love my DVR. I can record my shows and movies and watch them whenever I want. I know that when I record HD programs my DVR fills up fast. To account for that I often record shows in non-HD (SD format). This has me wondering: can I use some basic info that my DVR is giving to me to determine how many hours of HD and/or SD programming that my DVR can record? Check out the video to get started.

# Let’s get rich

There has been a lot of craziness in the stock market lately, but people who have invested their money in the markets could have made a lot of money in recent years. Students use yearly percent increase data to decide which stock: Apple, Netflix or Chipotle, they should have invested in, way back in 2007.

- What was the net gain of these stocks?
- How do you figure that?
- Does the arithmetic or geometric average of those increases equal their total gain or loss over the years?

Middle school students can access this activity by finding percent increases & decreases. Students can either approximate an annual growth rate or find an exact growth rate by finding the geometric mean of the growth rates. Older students can apply nth roots and write exponential functions to model investment growth over time.

# Labor Day

In this short activity, students learn the meaning and history of Labor Day as they look for patterns emerging from the Labor Day dates over the past years. Students then use those observed patterns to predict future dates of the holiday.

# How Much is a Tweet Worth?

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These days it seems everyone is on social media. Are you? Famous athletes and entertainers are on social media and they can make a lot of money. In this activity students study how the number of Twitter followers relates to tweet value. Is the relationship proportional, linear, exponential, something else? Students create a model and apply the model to determine the tweet value of stars like Katy Perry, Ronaldo, Barack Obama and others. You can also check out more data like this at http://opendorse.com/blog/