Category: Number Sense

String design, ellipses, and orbital mechanics

Artistic way to encourage understanding of a conic section.  Participants physically build an ellipse by choosing two foci and sketching the figure through a loop of string. While stitching an elliptical string design they puzzle about varying the foci spread and the loop length to create more extreme ellipses and are intuitively introduced to the measurement of eccentricity.

Celebrating Father’s Day

Thank you Mother and Father for all of those diapers – Which is a better deal, cloth or disposable diapers?  How much did you cost your parents in diapers?  In the future how much could your kid’s diapers cost?   Help…

What’s a payday loan? Good idea?

When you need a loan, and you’re desperate for help, is this a good idea? Students learn about this kind of loan and examine how it compares with personal loans and debt on your credit card.  They analyze final payments…

I bought toilet paper online

Students use the pictures in this activity to approximate the size of this 16 roll package of bamboo toilet paper. They use comparison ratios with our Ruth Bader Ginsburg doll to calculate the size of one roll and then calculate the size of 16 rolls. Funny activity.

Memorial Day 2020

This Monday Americans will celebrate Memorial Day.  Who are we honoring?  How did the holiday come about?  Isn’t Memorial Day usually on May 30th? Students learn a little about the history of the holiday, analyze the possibilities and patterns for when…

The AQI – Air Quality Index

See how much particulate matter, low-lying ozone, carbon monoxide, nitrogen dioxide and sulfur dioxide there is in the world’s atmosphere at any one time and place. Students learn about the scale of the AQI and search for some of the contributors to unhealthy locations.

Sadly, Jorge passed away yesterday.

Jorge would have been 15 years old on May 5, 2020. We wondered how old that would have been in human years. Does that 7 times his dog years formula really predict all dog’s aging?

Microns and Masks

How big is a coronavirus cell? How big is a micron? How well do these masks protect against the virus? What can you observe about the size of particles mentioned? Why are we wearing masks?

Stock Market headlines – Biggest losses since 2008

Biggest losses since 2008 – The Dow is measured in points but this decline can also be measured in the percentage lost.  Which way was the Dow being measured when this headline was produced?  Which method makes more sense? Wasn’t the initial value of the Dow much lower in 2008?

World record Snickers Bar

This World Record Snickers Bar was created in late January at the Waco, Texas Mars Wrigley Plant. What proportions would be an accurate cross sections of this monster bar? How many Mars Wrigley workers would this feed? How are your calculations different from what was published? How must their calculations have differed from yours?

Peeps

This activity is a investigation intended to get students and teachers to loosen up a little and appreciate how just considering a situation might lead you to a very reasonable approximation.
Too often students think that there is only one answer that is right and that the method for approaching that solution is also limited to the “correct” approach. Surely this fear of experimenting and guessing leads to math anxieties and the fear to reason and experiment.