# Cyphering Books

Are you smarter than a Colonial teenager?

Several years ago I wondered, How could the kilogram redefinition develop more quantum thinking in schoolkids around the world? I can't predict the future, but I found a precedent where kids learn what is taught for commerce and for science, from 200 years ago.

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Several years ago I wondered, How could the kilogram redefinition develop more quantum thinking in schoolkids around the world?

I can't predict the future, but I found a precedent where kids learn what is taught for commerce and for science, from 200 years ago.

The research of math professors Nerida Ellerton and Ken Clements provides one important precedent from American history, before and after the US adopted decimal currency in 1792.

Nerida and Ken research the history of school mathematics. Their findings on early math topics are based on their on a collection of 800+ cyphering books, which are handwritten schoolbooks from Europe, the UK, and the US, dated between 1607-1861. (For more details see my blog post about Nerida and Ken's collection of books, or their book Rewriting the History of School Mathematics in North America 1607-1861: The Central Role of Cyphering Books.)

Nerida and Ken see clear an increase in math problems which cover decimal currency as part of problems to practice business transactions. (Recall that NIST is part of the US Department of Commerce.)

The math professors also look at the relative amount of base-10 math problems between the US and England. Their research shows that US schoolchildren worked with base 10 math years before English schoolchildren.

In this video excerpt, Nerida walks me through a typical math problem from a cyphering book written before the US adopted decimal currency in 1792. Britain switched in 1971 from £sd to 100 pence per pound.

This particular Colonial-era problem reminds me of a contemporary problem in nutrition-cost-variety for food: Given a certain amount of money, what should you eat every day to stay on budget, in health, and not bored?

One real-life aspect not covered in this problem is the differences in weight between bushels of oats, rye, barley, and wheat. (The bushels are still different today.) The common factor was the currency, which here was British currency. I added some overlays to remind US viewers that there were 20 shillings to the pound and 12 pence to a shilling. When we don't know the units, we rely on conversion tables.

In the late 1700s Europe and the United States, decimal (base-10) was used more in the scientific fields before it migrated to essential, quotidian infrastructure like currency. Then, base 10 appears more in schoolbooks. With the 2018 Versailles vote on the kilogram (re)definition, Planck constant is connected to the infrastructure of our weights and measures. How soon will we see it in math and physics problems for schoolchildren?