## How did the Maya add and Subtract?

Instead of using a decimal system like ours, from 1-9, then 10, 20 etc., the Maya choose something very different, using a system of 20’s, having only 3 numbers, the dot = 1, the bar = 5, and a shell shape = 0.

They then read from the bottom of the page upwards.

So one row would contain dots and bars including ones and fives up to 19. The next row was x 20 which would include dots and bars up to 399 (20 x 20). The next row had dots and bars up to 799 (400 x 20).

What number is being shown in each of the images? (You will find the answers at the bottom of the page).

You can imagine then that the Maya were able to calculate extremely large numbers unlike for example, the ancient Greeks and Romans, as they had the concept of zero and place-values.

Their number system helped them to make really accurate astronomical predictions and they traced movements of the sun, moon, stars and even planets like Mars!!!!

**Activity:** Take the Maya Maths Challenge

Answers to test above:

a, 806

b, 2005