by Brayden Gateley
Recently I visited an old bookstore full of used books. Upon entering I saw the bookcases of the store like a brain: cluttered and full of memories. I was inspired to explore those tightly packed shelves where I uncovered an old, leather-bound math book, dating back to the 1760s from Dublin, Ireland. I was fascinated with it. What was math like back then? Why should math be studied?
I bought the book, tucked it under my jacket to protect it from the outside environment, and hurried to the nearest coffee shop to explore its contents. Upon opening it with care, I discovered it was a mercantile book that taught the rules of arithmetic. Surprisingly, I found that I was able to understand most of the Old English in the book. I discovered Ireland’s unit systems of troy weights and apothecary weights, as well as the avoirdupois weights which are the imperial system of weights we use today. I am fascinated by how the societies of our past were organized, with each system of weights being used for distinct purposes.
The book consists of arithmetic with whole numbers, vulgar fractions, decimals, and applications that relate to exchanges. The applications correlate with many of the concepts taught in modern Algebra classes: interest, rebates, commissions, brokers, profit/loss, and unit conversions. These were all taught using the same operations, fractions, and percents that are taught today.
Exploring math in the book reminded me of an old picture of me. I was around four, I wore baggy kiddy jeans and was surrounded by math workbooks of various levels laid out in an arch in front of me . This photo captured my love of math that began in early childhood. I have always had a curiosity with numbers and equations because I believe they are concrete ways of explaining the world and solving our problems.
I turned back to the book once more and found something astonishing: people from the 1700s were able to calculate square roots perfectly without a calculator – I checked their work. The examples in the book even consist of calculating square roots for numbers in the hundreds of thousands; every digit and decimal can be found! It is astonishing. I decided to tackle the challenge of learning this lost method. After a couple of hours of work, I was able to decipher their method and reproduce it. The look of astonishment on my friend’s face, when I showed him that the square root of 119,025 was 345 using nothing but pencil and paper is something I will never forget. It was a face full of awe and skepticism as if I had conducted witchcraft in order to come up with the answer.
I believe this math book is one of my most prized possessions, not because of its monetary value, but its sentimental value and what it represents. It is like a time capsule of math history. It describes the inner workings of math in 18th century commerce.
So, why should math be studied? For me, math is studied because it is the basis of problem solving through logical reasoning. Math can be used to model how the world operates, which has provoked my curiosity for as long as I can remember.