# STEM

On this page we will assemble (with your help!) suggestions for developing curricular materials that might be useful for teaching science, technology, engineering, and math with infused Mesoamerican cultural content.

Algebraic instruments from a late 19th-c. map (falsified) from Puebla. (Photo, S. Wood, Library of Congress, 2010)

#### Math: Vigesimal System

The root 20, or vigesimal system — in contrast with the Western decimal system — runs across Mesoamerican Cultures.  One can reflect with children how both of these systems might have developed (10 fingers, or 20 digits, if we include toes). Note how, in the image below, we see that a single dot, the symbol for the number one, can also be seen in glyphs as one finger, which adds to our theory about counting our human digits.  The number twenty is represented by a flag (which can come in various shapes).  The number four hundred (20 x 20) is a feather.  The number 8,000 is a sack that once may have held 8,000 cacao beans or pieces of incense.  The bottom row in the image below shows us how number glyphs were combined with iconography representing very common items of preciosity and tributes, such as masks made of precious stones, larger sacks of cacao beans, sacks of cotton, and bolds of cotton cloth or cloaks.  Notices that the number 100 (bags of cacao) is represented by five flags, i.e. 5 x 20.  The 402 cotton cloaks shows the folded cloak and, above it, to fingers (2) and one feather (400).  This kind of material can provide fun math projects for children.

Some Nahua counting glyphs (a screenshot of a message posted to Facebook by Carlos Carrillo Suárez, 2013)

One can also explore how this system is reflected in the calendars that Mesoamericans developed.  Mesolore hosts a video where Anthony Aveni speaks about “Mesoamerican Mathematics,” including a discussion about gestures and writing, living numbers, numbers and time, Vigesimal versus Decimal, Base-Twenty  Notation Numbers in History, the Maya Books, Venus and Mathematics, the Heliacal Rise, Carting Venus, the Number Zero, the Number 584, and Astrology.

#### Math:  Geometry

Here is a link to a PowerPoint presentation by Stephanie Wood about pyramids and geometrical shapes, angles, vocabulary, and more, as an initial effort in imagining what might be taught about math using Oaxacan indigenous cultures or Spanish colonial culture as a starting point.  We welcome the input and improvements by math teachers!

Sun symbol. Search tonatiuh in the Nahuatl Dictionary. Florentine Codex (public domain)

The tail of a comet. Search pocyotl in the Nahuatl Dictionary. Image from the Florentine Codex (public domain)

#### Astronomy

Many pre-Columbian settlements were laid out in alignment with the movement of the sun, and the solstice was especially notable. The importance of astronomy to indigenous Americans is more and more obvious as scholars take a closer look at settlement patterns.  If this topic interests you, be sure to ask our resident archaeologist to refer to alignments when we are in the field.

“X” Shaped, Four-Part Division of Tenochtitlan (reproduction from the Codex Mendoza)

#### Ethnobiology

In this institute we will have more content relevant for developing ethnobiology units than any other STEM curricula, which has prompted us to prepare a number of sub-pages on this topic. We are open to expanding these possibilities.  But we also hope you will also suggest additional STEM projects that strike you as possible given the institute foci.

Here is a Mesolore interview with Alejandro de Avila, of Oaxaca, speaking about ethnobiology and ecology (go a bit more than 2 minutes into this video to here what he says about the subject).  This video is in Spanish with English subtitles.  This person has been involved in the creation of the ethnobotanical garden and serves as its director. He was also instrumental in developing the textile museum.

Another Mesolore interview, with Ellen Messer, includes a discussion of the science of maize and its transformation into food, as it was prepared with limestone.  This interview is in English with Spanish subtitles. Go to the point at about 4:40 minutes to hear her scientific explanations. She also speaks about chilies and chocolate and their roles in the Mesoamerican diet, including nutrition, taste, and digestion.

A third Mesolore interview that is relevant for ethnobiology, with Julieta Ramos-Elorduy, discusses edible insects in their various life stages, the use of bugs for their medicinal value, and their role in feeding on waste and converting themselves into a protein for feeding animals, such as chickens. Scientists are measuring the effect these waste-eating insects can have on animal growth, reproduction, and coloring (yolk, feet, beak, and meat).

Here are some pages we have begun to develop, relating to ethnobiology:

#### Technology

We would love some suggestions about ways of teaching technology by using Oaxacan indigenous and Spanish cultures as a launching pad.  Some areas where we have photographic stills and moving images are:

Candle making, Florentine Codex, Book 10, Chap. 25 (public domain)

The backstrap loom. Florentine Codex, Book 10, Chapter 10 (public domain)

#### Wikipedia

Wikipedia offers a page with links to Science and Technology of Mesoamerica

#### IAGO Library

The free library at the Instituto de Artes Gráficos de Oaxaca, on Macedonio Alcalá, has some books that might be useful for STEM projects.  See, for example, the book below…

Book by Stephen Wilson in the IAGO library.