Not every number system is like our familiar Arabic numerals. The Aztecs' pictographic number system used symbols such as dots, lines, arrows, and hands to represent certain values: a dot was the number one, a line was the number five, and two lines were the number ten. This can make Aztec mathematics a little harder for students to grasp. To help them understand Aztec math, develop projects to give them a grounding in Aztec numbers.

## Decoding Aztec Numbers

Make a worksheet explaining some of the basic Aztec numbers. The representation system becomes more complex as numbers go higher: a vertical line connected to a rectangle in the shape of capital P represents the number 20. A large symbol for the number 20 connected by a diagonal line to a small number 20 symbol represents the number 400, or 20 times 20. Ask students questions and discuss why the Aztecs might represent their numbers this way. Ask about the relationship between symbols.

## Translating Aztec Numbers

Make two columns on several large poster boards. In one column, draw out a series of Aztec numbers on each poster board. Make each board unique. Divide the students into groups and have them work on translating the numbers into Arabic numerals. Go over the answers as a class. Then, have the students translate significant numbers in their lives, such as their birthday, a holiday, or a significant historical date, into Aztec numbers.

## Aztec Fractions and Maps

The Aztec system of fractions has only recently been decoded. Special symbols, such as hearts and arrows, represented fractional numbers in the Aztec system, as well as numbers that could not be represented by multiplying two whole numbers together, unlike 20 times 20 for 400. The Aztecs primarily used these special units of measure on maps. Make copies of Aztec maps, complete with units of measurement and keys, to help students visualise the system. Then, have them make their own maps using Aztec fractions

## Aztec Word Problems

Translate every day math word problems so that they use Aztec numerals rather than Arabic ones. If possible, relate the problems to Aztec culture, for example adding up ears of corn or measuring height of a temple. Have students solve the word problems and record their answers in Aztec numerals. Then, have the students write their own word problems and give them to each other to solve. Check their work.