Killing bacteria

Use the need for cleanliness during flu season to engage your students.

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Does it really matter whether you kill 99.9% of the bacteria or 99.999% of the germs?

In this 3-act activity we've asked students to consider whether these claims about these two wipes' efficacy really make a difference.  We've supplied students with a list of bacteria counts on various surfaces and asked them to calculate how much of a difference these two different percents make in wiping out germs.

This is an excellent opportunity to deal with repeating decimals.  Thanks to Kyle Berry for sharing this image with us!

Movies and the upcoming Oscars

We have 11 activities for your Oscar week.

Highest Grossing Movies - Let your students develop their own ideas about compounded percent change while they have the opportunity to speak about the upcoming Academy Awards show. Worldwide box office income is compared for the top ten grossing movies of all time. Is total gross the most appropriate way to judge the popularity of a movie?  How does inflation and increasing ticket prices come into play? Inflation rates are used to let students calculate how the money of 1997 compares to the money of 2013. Students see for themselves what exponential growth means.

Is the Iditarod really the Last Great Race on Earth?

The Iditarod Dog Sled Race begins on Saturday, March 4th in Anchorage, Alaska. This long and grueling competition is called the Last Great Race on Earth. Students do some rate, distance, and hardship comparisons to decide if they agree that the Iditarod is really the Last Great Race on Earth.

Dallas Seavey drops down the bank onto the Yukon River shortly after leaving the village checkpoint of Ruby at sunset in Interior Alaska during the 2010 Iditarod

Dallas Seavey drops down the bank onto the Yukon River shortly after leaving Ruby at sunset in Interior Alaska during the 2010 Iditarod

Opening weekend The Black Panther

Can you tell from its opening weekend how much the new movie, Black Panther, might earn in theaters?  This activity can be used anytime and is especially timely when there is a new blockbuster movie released.  We've left blank spaces in our chart for students to add their favorites or for future movies. The data for this activity can be found at:  Just click on any movie and look for this info: Total&Lifetime
Students compare "Opening Weekend" amounts to "Total Lifetime Gross (Domestic)" data to try to  predict how much money the new Black Panther movie (which earned $203,000,000 in its opening weekend in the U.S.) will make at theaters. This task is accessible for any student who can plot points on a grid, so it could be used for students as young as 4th graders.  Older students can create a line of best fit and equation to model the data and make predictions.  By plotting and analyzing the data students decide if they can, in fact, predict the future.



Friction, score-keeping, trajectory and weirdness are the main concepts in this activity.  Curling is not a well-understood sport but the science and strategy are easily understood and enjoyed.

Let your students watch this video to get a feel for the sport before they try the activity.

Is this a Leap year?


Will we have a 29th of February this year?  How can you tell?

Students work with a flow chart to deduce what years are going to be leap years.  They learn about the exact measurement of a solar year and how our Gregorian calendar needs to be adjusted to accurately align the calendar with the Earth's revolutions around the Sun.