## Why Not Just Teach the Traditional U.S. Algorithm?

Taking too long?

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# Fourth Graders Participated in a Political Art Installation, and then Posed Mathematical Questions About It.

“It’s my first political performance and I just felt I had to do it now. I wanted to show that any wall is dismantlable. We, the public, can tear down walls when society gets together. It could be a mental, physical, or political wall – the point is, it’s ephemeral.”Bosco Sodi, Artist

# Estimating Protest Crowd Size Using the Jacob’s Method of Crowd Counting.

“For many events, especially political rallies or protests, the number of people in a crowd carries political significance and count results are controversial”- Wikipedia

“Almost everyone who has tried to make a crowd estimate has a vested interest in what the outcome of the estimate is”– Charles Seife, Professor of Journalism and Mathematician at NYU.

Fourth graders applied the Jacob’s method of crowd counting to estimate the protest crowd that gathered in Washington Square Park on Wednesday, January 25th, 2017. The emergency rally was organized in response to President Trump’s executive order implementing a ban on immigrants entering the country from large Muslim populations, including Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen.

# Getting the Numbers Right: The Jacobs Method of Crowd Counting

Herbert Jacobs, a University of California journalism professor in the 1960’s, devised a basic density rule that has been widely accepted. Watching students protesting the Vietnam War from his office window, Jacobs saw that had gathered on a plaza that was arranged in a grid. He counted those in a few squares to get an average number per square and multiplied that by the total number of squares. He also came up with a basic density rule that states a “light crowd” has one person per square meter, and doubled that for a “dense crowd”. A “heavy crowd” would have as many as four people per square meter, according to this method.

# Using People Per Square Meter as Density Factors to Determine Crowd Size.

One person per square meter

Three people per square meter

Nine people per square meter

Six people per square meter

# Washington Square Park Diagram Showing Density Arrays.

Six people per square meter density computation

Nine people per square meter computation

# Math with Social Justice Relevance

It was a chilly day in January.

Fourth grade students and teachers went downtown to walk the streets of the busy financial district to meet food cart vendors. They were able to observe the variety of international selections that vendors were selling, and sample the delicious-smelling food.

Over 90% of the food vendors in New York City are first generation, or recent immigrants. This field trip gave students the opportunity to talk directly to the people who stood inside these carts, cooking food that reflected the cuisine of their home countries. Students were curious to hear the stories of where they immigrated from, and how they happened to enter into the business of selling food on the street. Continue reading

## Family Math Night at LREI

### Students and Parents look forward to Family Math Night every year.

Students in grades one through four celebrate mathematics, as well as continue to hone their fluency in combination facts by playing fun games. Fourth grade students create their own math games as a capstone experience, and then teach them to family and friends during Family Math Night. Continue reading

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## Grade 4, Macy’s Thanksgiving Day Parade and Multiplication Arrays

Lakota Band leader, Greg Snyder, has a math problem:

How can 272 band members, playing 15 different instruments be placed into arrays that can fit onto a street that’s 57 feet wide?  Continue reading