When are the Schur product and the matrix product of two matrices the same? With the help of Morpheus (from The Matrix) and more, we explore this question and find both mathematical answers and math-memes.

We present a detailed look at one small section of a premodern algebra manuscript from circa 1365 C.E. The manuscript, Tratatto dell’Alcibra Amuchabile (Anonimo), is written in the Tuscan vernacular, with no symbols, no punctuation, and wildly inconsistent (pre-printing press) spellings. We present some of the hurdles to translating this “rhetorical algebra” followed by an annotated translation of one of its algebra rules, Rule 5, through which we learn the methods and mindset of algebra that preceded and seeded the breakthroughs in algebra of the 16th century. We also point to some of the significant differences between algebra then and now. Finally, we zoom out to the cultural setting that informed the applied mathematics of the day.

We model prejudice in the context of an iterated prisoner’s dilemma tournament. Prejudice here is defined as the inability to distinguish amongst members of an identifiable group. We run a computer simulation where agents of one of two groups with defined strategies are randomly matched against each other. The agents either cooperate with or defect against the agent they are matched with. Our focus is on agents who play an unprejudiced version of the Tit-for-Tat strategy (cooperate with any player in the first encounter, and then apply the same strategy [defect or cooperate] that the opposing player played against them in the last encounter) and a prejudiced strategy (cooperate with any member of the other group in the first encounter with a member of the other group, and then apply the same strategy [defect or cooperate] that any member of that group played against them in the last encounter with a member of that group). We find that even though agents are initially inclined to give members of another group the benefit of the doubt when interacting with them, the introduction of very minor levels of defection, real or perceived, can lead to universal defection against members of the other group.

We explore probability exercises based on the game UNO. Excluding the Wild cards, the deck contains precisely 100 cards, which makes it convenient to express probabilities as percentages. We discuss the mathematical relation between cards that can be played after other cards. We also propose an algebraic exercise that relates several quantities, such as the number of cards left in the losing player’s hand. Finally, we argue that UNO is a very inclusive game: it is logistically easy to play, allows for players of different skill levels, and can be adapted to meet special needs. Beyond being playful exercises, our activities demonstrate that mathematical thinking can be applied in a variety of contexts.

Math circles are a common form of outreach usually run by professional mathematicians as enrichment for K-12 students or teachers. As a setting to stimulate interest and develop positive socialization around mathematical practice, a regular math circle can also be an effective bridge to higher education in carceral settings for both facilitators and participants. This article describes my journey through starting and running math circles in county jails, with a view towards the expansion of mathematics education as another tool for the dismantling of mass incarceration.

A meme is a graphical concept or cultural item that is disseminated via the Internet, often through social media platforms. Memes serve as a mechanism for replicating cultural traits by incorporating aspects of cultural mutation and evolution. The potential of memes in learning and education has been emphasized in several recent studies. The present article examines the impact of memes in increasing public engagement with mathematics and mathematical concepts. By focusing on memes that exhibit specific attributes—such as emotional facial expressions of recognizable human characters and dialogues emphasizing the usefulness or beauty of a mathematical concept—we observe a significant increase in the number of views received by both memes and their associated videos that introduce mathematical concepts. We conclude that memes are indeed an effective approach to increase public engagement with mathematics and mathematical concepts.

Interlace: A journal of mathematics and fiber arts is a peer-reviewed, open-access completely free journal devoted to publishing high-quality original research at the intersection of mathematics and fiber arts. The journal is now accepting submissions.

Through a conversation between Small Number and his Auntie, this article describes the Throwing Game, a Haida tradition recorded by John Swanton in 1905. Several mathematical concepts that may be associated to the game are mentioned.

"Euclidean Vision" is a short poem that evaluates geometry from a humanistic perspective, focusing partly on its pleasures. Geometry gives us the pleasing assurance of certainty. It does this through the radical abstraction of space and form, which makes possible a completeness of mathematical vision based on axioms. It's this purity that guarantees a knowledge that "can go on forever." In the end, the poem points to the wonderful freedom that geometry and other mathematical disciplines give us in the midst of difficult and confusing lives. In its beauty and universality, geometry stands as an eternal aspect of the human project. Because we can see that mathematics transcends history and cultures, we may feel inspired to work together to protect the viability of our shared world.

In the Kingdom of K, on the Planet Pemdas, numbers were more important than people.As far back as anyone could remember, it had been this way.By the time a child took its first steps, its aptitude matrices would have been recorded, compiled, and reported every month to the Department of Numerology.Once this occurred, the child's life course could not be altered.The matrices and methodologies to obtain them were considered state secrets and viewed by outsiders as the main reason why K produced the world's most respected scholars and thinkers.These surveys analyzed children from head to toe, ear to ear, and inside out.There was no physical or mental aberration without a corresponding rating and value.That indiscernible mole hiding in the shadow of its gargantuan cousin on little Violet's face?Scored, ranked, and filed.