Abstract: Everyone knows that the ratio of the circumference of a circle to its diameter is a constant number that is the same for all circles, and this number is called π. This conclusion can be reached by asking the question: why are all circles similar to each other? Because of this similarity, it is natural to assume proportionality in their linear dimensions.

The fact that the ratio of the circumference of a circle to its diameter is constant has been known since ancient times. The first use of this number's symbol, the Greek letter π, is found in the work “Synopsis Palmariorum Matheseos” (“Overview of Mathematics Achievements”) by the English teacher William Jones (1675–1749), published in 1706. The symbol π for the ratio of the circumference to the diameter became widely used after it was employed in the works of Leonhard Euler (1707–1783) — one of the greatest mathematicians in history. His work spans all areas of mathematics and he wrote 80 volumes of research.

We will give a mathematically rigorous definition of π by actually proving that the ratio of the circumference of any circle to its diameter is a constant value.

Jan 31, 6:00 - 7:45pm. (Pizza at 6, presentation at 6:30)
~~~In-person with option to attend online~~~
Speakers: Marissa Assam Andrecyk (Dalhousie, with Imhotep's Legacy Academy )

Topic: How Many Handshakes?

Abstract: Counting techniques are very important in many areas of mathematics. In this presentation, students will look at a classic counting problem and its variations as a brief introduction to combinatorics. They will be encouraged to try their own solutions and share their ideas. Those on zoom will need pencil and paper.

 

November 29, 6 - 7:45pm. (Pizza at 6, presentation at 6:30)
~~~In-person with option to attend online~~~
Speaker:Iresha Madduwe Hewalage (Dalhousie)

Topic: Problem Solving

Abstract: Problem solving is central to mathematics. In this presentation we will work on a series of fun and challenging problems. Students will be encouraged to attempt their own solutions and share their ideas with us. If joining us on Zoom, you'll need pencil and paper.

 

October 25, 6 - 7:45pm. (Pizza at 6, presentation at 6:30)
~~~In-person with option to attend online~~~
Speaker: Bram Ogus (Dalhousie)

Topic: When Math Stops Making Sense

Abstract: When we think of Mathematics, we don't usually think about problems that contradict our intuition. Seemingly valid proofs for things that should obviously be false. When we look at paradoxes, everything we know about math is flipped on its head. All horses are pink, we can create perpetual motion using only a cat and a slice of toast, we can fill up an infinite hotel with infinite people and still have more space, and so much more. In this presentation, we will explore the world of the paradoxical by learning and using some basic notions of set theory like union and intersection, cardinality, and induction.

 

September 27, 6 - 7:45pm. (Pizza at 6, presentation at 6:30)
~~~In-person with option to attend online~~~
Speaker: Tom Potter (Dalhousie)

Topic: Dots and Boxes

Abstract: Dots and Boxes is a game invented by French mathematician Édouard Lucas, who first published a paper on it in 1895. Lucas called it la pipopipette. It is generally a two-player game, although it can be adapted to three or more players. The game is played on a grid of dots, and the goal is to form the most boxes by filling in edges between the dots. Dots and Boxes is an excellent introduction to games involving strategy. Learning this game can increase your capacity for strategic thinking, but it is also a lot of fun! We will guide you through the simple rules by going through an example, and then let you play and experiment to see what outcomes you can achieve. If time permits, the audience can play a round against the presenter!

 

Topic Ideas?

If you have a request for topics, please contact us. If you have a topic or idea that appeals to you, let us help you explore it! Email our team at mathcircles@dal.ca and we will try to work it into our repertoire.