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Issue 6   |  November 28, 2018

Derech Emunah Newsletter
"Thanksgiving Day" Math -- Students Apply Algebra to Timely, Real World Situations

By Dr. Dorothea Eberz-Wagner, Math Teacher


During the week before Thanksgiving, the students in Algebra 2 worked on a math problem that fit right into the theme of Thanksgiving.

It is about a group of caring people who plan a Thanksgiving dinner for the homeless. The menu includes pumpkin pie and fruit salad for dessert. As people are preparing for the dinner, they need to make sure that they will have enough desserts for the vast number of people that they are expecting and that the volunteers will be able to prepare the sweets in a given amount of time. Also, at least five pies and a certain number of bowls of fruit salad must be made.


All of these requirements can be modeled by setting up suitable linear inequalities. The goal now is to choose the number of pies and bowls of fruit salad which will minimize the cost for the dessert.


Mathematically speaking, this is a problem in linear programming, the cost function being a linear function in the variables x (number of pies) and y (number of bowls of fruit salad).  As the students were working on this puzzle, they learned about:


   •    Mathematical modeling
   •    How to use a graph to represent the possible pairs (x,y) which satisfy all the given inequalities
   •    How to find the vertices of that region by solving systems of linear equations and
   •    The vertex principle of linear programming


It is a math problem involving many steps, building on topics from Algebra 1. Yet, it is concrete and presented in an everyday context that the students can relate to.


The problem can be adjusted to find other ‘best outcomes.' For instance, how do we maximize total sales or profit given a system of linear constraints?


By using a relevant, easy to understand problem, the students were highly motivated to dive right in. It also helped them better appreciate mathematical concepts. As a result, I believe our students are now more confident to use math for other real-life applications.




Below: Left to right: Esti Toban, Rachel Eisenstein, Shifra Wren


Further below: Standing left to right: Yael Genauer, Kaden Balkany, Shifra Wren, Aliza Margolese, Rachel Eisenstein. Seated: Esti Toban

Upcoming Dates and Events


November 29th
Rabbi Elazar Meisels, Head of Sara Schnierer

will give a presentation and share information

about his College program.


December 5th

Chanukah Chagiga


December 11th
Dr. David Luchins, Founding Dean, Professor, Chair, Political Science Department of Lander College for Women (TOURO) will be at DE to speak to our students


December 15th 
Derech Emunah Shabbaton with Mrs. Mindy Lankry


Rebbetzin Lankry has served as Rebbetzin alongside her husband Rabbi Aaron Lankry in several synagogues around the world, including Hong Kong, Edmonton, Alberta (Canada), Aventura, Florida and Sephardic Synagogue of Fifth Ave, Manhattan, NY.


Mrs. Lankry is a certified life coach, gives various Torah lectures, as well as private classes on family purity. 


She recently authored and published a book, Parsha in Pink, which gives weekly inspiration from the Torah for the busy women of today.


The Rebbetzin now resides in Monsey where her husband is Rabbi of Congregation Ohr Chaim. They have eight children and several grandchildren.



December 18th
Fast of Asarah B’Tevet - Early Dismissal at 12:45 pm


December 19th
Ulpaniada Semi-Finals - An International problem-solving competition based on math skills and logical reasoning. All four of our Derech Emunah participants made it to the Semi-Finals


Read more about the Ulpaniada:

December 24th - January 1st

Winter break - No school


Date to be announced

A Musical Production


by Derech Emunah Students


Derech Emunah Girls