Among their many achievements, the Mayan civilization was the first to understand the power of zero. This card game uses their principles and symbols to bring math alive for kids and help them understand positive and negative numbers. Each player gets a number line on which they can measure their progress, from -5 to 5. They are then dealt cards with numbers on them, and secret tokens. All tokens and cards feature both Arabic numerals and Mayan number symbols. Your goal is to add and subtract your cards to reach your secret token number. But be careful or you may plunge into the world of negative numbers!